Thymoma and thymic carcinomas

Treatment of thymoma with low-dose glucocorticoids before surgery for significant tumor shrinkage: A case report

BACKGROUND

Thymic epithelial neoplasms are rare malignant neoplasms originating in the thymus gland. There have been case reports of patients with advanced thymomas treated with a methylprednisolone pulse or with glucocorticoid (GCs) shock before surgery, followed by surgical treatment, all of whom achieved good results. The effect of GCs on thymomas is related mainly to the action on GC receptors in thymic lymphocytes and epithelial cells. GC receptor expression has been associated with a better prognosis in patients with thymomas, including those with surgically removed thymomas.

CASE SUMMARY

We report a case of a patient with thymoma who had a significant response to preoperative low-dose GC therapy. A mediastinal tumor was detected in the patient via computerized tomography upon admission. The tumor was initially suspected to be a thymic tumor, but lymphoma could not be ruled out. The tumor shrank significantly after low-dose (5 mg/day) GC therapy. Thoracoscopic thymoma resection was performed after puncture pathology was confirmed. The patient recovered well after the operation and is currently performing well with no recurrence of the tumor.

CONCLUSION

This case highlights that low-dose GCs are effective in the treatment of thymomas, and we believe that GCs should be applied more frequently and studied more thoroughly in the treatment of thymomas.

Clinical application of standardization right thoracic incision for thoracoscopic thymic tumor resection

BACKGROUND

With the continuous development of minimally invasive thoracic surgery, thoracoscopic thymectomy has become a routine operation. This method, now widely recognized, better protects lung function, reduces intraoperative blood loss and pain, and shortens postoperative hospital stay. We now introduce a standardized right thoracic incision for thoracoscopic thymic tumor resection, which has achieved favorable clinical outcomes.

METHODS

This retrospective study involves 63 patients who underwent standardized right thoracic incision for thoracoscopic thymic tumor resection from October 2022 to January 2024. We analyzed the relevant clinical data, including postoperative pathological diagnosis, operation time, intraoperative blood loss, chest tube drainage duration, postoperative hospital stay, and follow-up data.

RESULTS

All 63 patients underwent thoracoscopic surgery. Thoracoscopic surgery excised thymic tumors and mediastinal fat in 62 cases, while 1 case of thymic carcinoma underwent thoracoscopic biopsy due to invasion of the superior vena cava and innominate vein. Postoperative pathological diagnosis revealed thymoma in 35 cases (33 cases of thymoma and 2 cases of thymic adenocarcinoma). R0 resection was achieved in 33 cases and R1 resection in 1 case. Additionally, 2 patients diagnosed with thymic adenocarcinoma were advised to undergo postoperative radiotherapy. Postoperative pathological diagnosis of the other 28 cases showed thymus hyperplasia in 13 cases and thymus cysts in 15 cases. The mean operation time was 57.3 ± 14.2 min, and intraoperative blood loss was 22.5 ± 14.7 ml. The mean chest tube drainage duration was 2.7 ± 1.3 days, and the postoperative hospital stay was 3.7 ± 1.4 days. No secondary operations were required, and no severe complications or mortality were observed during the perioperative period. All patients were discharged smoothly after surgery. Ten patients were not followed up due to recent surgery. The remaining 53 patients were followed up for 6 to 12 months, with no recurrence or distant metastasis observed.

CONCLUSION

The standardized right thoracic incision for thoracoscopic thymic tumor resection simplifies the procedure of thymectomy. The operation's risk points are relatively fixed, making it safe and feasible. It is easy for the operator to master, and the thymic tumor resection rate is high. It possesses characteristics of being minimally invasive, enabling rapid recovery, having fewer complications, and requiring simple perioperative management.

DNA methylation analysis of multiple genes in thymic epithelial tumors

Aim: To investigate DNA methylation levels of a panel of genes in thymic epithelial tumors (TETs).Materials & methods: We selected 15 genes among the most promising epigenetic biomarkers of TETs and evaluated their methylation levels in 71 TET samples.Results: thymic carcinomas (TCs) showed hypermethylation of GHSR and ELF3 genes and reduced IL1RN methylation levels compared with thymomas (TMs) and healthy thymic tissues. RAG1 was hypomethylated in TMs compared with healthy thymic tissues. No difference in the methylation levels of the investigated genes was seen among TM stages and subtypes. No changes in blood methylation levels of the investigated genes were seen among TET subtypes.Conclusion: The present study confirms GHSR, ELF3, IL1RN and RAG1 as TET epigenetic biomarkers.

Application of machine learning for the differentiation of thymomas and thymic cysts using deep transfer learning: A multi-center comparison of diagnostic performance based on different dimensional models

OBJECTIVE

This study aimed to evaluate the feasibility and performance of deep transfer learning (DTL) networks with different types and dimensions in differentiating thymomas from thymic cysts in a retrospective cohort.

MATERIALS AND METHODS

Based on chest-enhanced computed tomography (CT), the region of interest was delineated, and the maximum cross section of the lesion was selected as the input image. Five convolutional neural networks (CNNs) and Vision Transformer (ViT) were used to construct a 2D DTL model. The 2D model constructed by the maximum section (n) and the upper and lower layers (n - 1, n + 1) of the lesion was used for feature extraction, and the features were selected. The remaining features were pre-fused to construct a 2.5D model. The whole lesion image was selected for input and constructing a 3D model.

RESULTS

In the 2D model, the area under curve (AUC) of Resnet50 was 0.950 in the training cohort and 0.907 in the internal validation cohort. In the 2.5D model, the AUCs of Vgg11 in the internal validation cohort and external validation cohort 1 were 0.937 and 0.965, respectively. The AUCs of Inception_v3 in the training cohort and external validation cohort 2 were 0.981 and 0.950, respectively. The AUC values of 3D_Resnet50 in the four cohorts were 0.987, 0.937, 0.938, and 0.905.

CONCLUSIONS

The DTL model based on multiple different dimensions can be used as a highly sensitive and specific tool for the non-invasive differential diagnosis of thymomas and thymic cysts to assist clinicians in decision-making.

Unveiling Thymoma Typing Through Hyperspectral Imaging and Deep Learning

Thymoma, a rare tumor from thymic epithelial cells, presents diagnostic challenges because of the subjective nature of traditional methods, leading to high false-negative rates and long diagnosis times. This study introduces a thymoma classification technique that integrates hyperspectral imaging with deep learning. We initially capture pathological slice images of thymoma using a hyperspectral camera and delineate regions of interest to extract spectral data. This data undergoes reflectance calibration and noise reduction. Subsequently, we transform the spectral data into two-dimensional images via the Gramian Angular Field (GAF) method. A variant residual network is then utilized to extract features and classify these images. Our results demonstrate that this model significantly enhances classification accuracy and efficiency, achieving an average accuracy of 95%. The method proves highly effective in automated thymoma diagnosis, optimizing data utilization, and feature representation learning.

Risk stratification of thymic epithelial tumors based on peritumor CT radiomics and semantic features

OBJECTIVES

To develop and validate nomograms combining radiomics and semantic features to identify the invasiveness and histopathological risk stratification of thymic epithelial tumors (TET) using contrast-enhanced CT.

METHODS

This retrospective multi-center study included 224 consecutive cases. For each case, 6764 intratumor and peritumor radiomics features and 31 semantic features were collected. Multi-feature selections and decision tree models were performed on radiomics features and semantic features separately to select the most important features for Masaoka-Koga staging and WHO classification. The selected features were then combined to create nomograms for the two systems. The performance of the radiomics model, semantic model, and combined model was evaluated using the area under the receiver operating characteristic curves (AUCs).

RESULTS

One hundred eighty-seven cases (56.5 years ± 12.3, 101 men) were included, with 62 cases as the external test set. For Masaoka-Koga staging, the combined model, which incorporated five peritumor radiomics features and four semantic features, showed an AUC of 0.958 (95% CI: 0.912-1.000) in distinguishing between early-stage (stage I/II) and advanced-stage (III/IV) TET in the external test set. For WHO classification, the combined model incorporating five peritumor radiomics features and two semantic features showed an AUC of 0.857 (0.760-0.955) in differentiating low-risk (type A/AB/B1) and high-risk (B2/B3/C) TET. The combined models showed the most effective predictive performance, while the semantic models exhibited comparable performance to the radiomics models in both systems (p > 0.05).

CONCLUSION

The nomograms combining peritumor radiomics features and semantic features could help in increasing the accuracy of grading invasiveness and risk stratification of TET.

CRITICAL RELEVANCE STATEMENT

Peripheral invasion and histopathological type are major determinants of treatment and prognosis of TET. The integration of peritumoral radiomics features and semantic features into nomograms may enhance the accuracy of grading invasiveness and risk stratification of TET.

KEY POINTS

Peritumor region of TET may suggest histopathological and invasive risk. Peritumor radiomic and semantic features allow classification by Masaoka-Koga staging (AUC: 0.958). Peritumor radiomic and semantic features enable the classification of histopathological risk (AUC: 0.857).

Constitutional Factors and Irradiation as Risk Factors for Thymoma: A European Case-Control Study

Little is known about the aetiology of thymoma. This study aims to identify medical risk factors for thymoma as a systematic approach to new hypotheses on the aetiology of this disease. A European multi-centre case-control study was conducted from 1995 to 1997, including incident cases aged 35-69 years with thymoma. Altogether, we accepted 85 cases and 3350 controls, of which we interviewed 77 cases and 2071 population controls about constitutional factors, medical examinations, and former diseases. Odds ratios (ORs) with 95% confidence intervals (CI) were calculated. Medical examinations with X-ray or radiotherapy performed >20 times at least one year before the thymoma diagnosis indicated a possible risk factor for thymoma (OR 1.58, 95% CI 0.93-2.69). Having the first radiotherapy treatment at least one year before the thymoma diagnosis yielded an OR for thymoma of 2.39; 95% CI (0.96-5.99), and if it was at least five years before, the OR for thymoma was 2.81; 95% CI (1.03-7.72). Having a red/auburn hair colour was associated with thymoma, (OR 3.6, 95% CI 1.4-9.5) whereas having pigmented skin was slightly associated with thymoma (OR 1.8, 95% CI 0.8-3.8). Over twenty instances of X-ray examinations or radiotherapy were identified as potential risk factors for thymoma, along with certain constitutional factors. The observed correlations between benign tumours and thymoma could stem from an inherent predisposition to tumour development or result from detection bias. Given that this is the initial analytical study examining medical risk factors for thymoma, all of the results should be approached with caution, acknowledging the possibility that some findings might be incidental.

Thymic epithelial tumor medical treatment: A narrative review

Thymic epithelial tumors, a malignancy originating in the thymus, are the commonest primary neoplasm of the anterior mediastinum; however, among thoracic tumors, they have a relatively low incidence rare. Thymic epithelial tumors can be broadly classified into thymic carcinoma and thymoma. As the cornerstone of thymic tumor treatment, surgery is the preferred treatment for early-stage patients, whereas, for advanced unresectable thymic tumors, the treatment is chemoradiotherapy. Targeted therapy is less effective for thymic tumors. Moreover, the use of immune checkpoint inhibitors as another effective treatment option for advanced unresectable thymic tumors, particularly thymomas, is limited owing to immune-related adverse effects. Here, we have summarized all pertinent information regarding chemotherapy, especially preoperative neoadjuvant chemotherapy, and chemotherapy in combination with other treatments, and reviewed the effectiveness of these procedures and recent advances in targeted therapy. In addition, we analyzed the efficacy and safety of immune checkpoint inhibitors in thymic epithelial tumors, to provide a holistic treatment view.

A comprehensive review on lncRNA LOXL1-AS1: molecular mechanistic pathways of lncRNA LOXL1-AS1 in tumorigenicity of cancer cells

Long non-coding RNAs (lncRNAs) are versatile RNAs that regulate various cellular processes, such as gene regulation, by acting as signals, decoys, guides, and scaffolds. A novel recognized lncRNA, LOXL1-antisense RNA 1 (LOXL1-AS1), is dysregulated in some diseases, including cancer, and acts as an oncogenic lncRNA in many types of cancer cells. Upregulation of LOXL1-AS1 has been involved in proliferation, migration, metastasis, and EMT, as well as inhibiting apoptosis in cancer cells. Most importantly, the malignant promoting activity of LOXL1-AS1 can be mostly mediated by sequestering specific miRNAs and inhibiting their binding to the 3´UTR of their target mRNAs, thereby indirectly regulating gene expression. Additionally, LOXL1-AS1 can decoy transcription factors and proteins and prevent their binding to their regulatory regions, inhibiting their mechanistic activity on the regulation of gene expression and signaling pathways. This review presents the mechanistic pathways of the oncogenic role of LOXL1-AS1 by modulating its target miRNAs and proteins in various cancer cells. Having information about the molecular mechanisms regulated by LOXL1-AS1 in cancer cells can open ways to find out particular prognostic biomarkers, as well as discover novel therapeutic approaches for different types of cancer.

Rechallenge immunotherapy after immune resistance in patients with advanced thymic carcinoma

BACKGROUNDS

Immunotherapy is effective for patients with advanced thymic carcinoma (TC). However, the effectiveness of rechallenge immunotherapy in patients who are resistant to immunotherapy has not been investigated.

METHODS

Thirty-five patients with advanced TC using immunotherapy between 2016 and 2023 at Zhejiang Cancer Hospital, The Second Affiliated Hospital of Nanchang University, and Fujian Cancer Hospital were evaluated in this study. Tumor response was evaluated according to the Response Evaluation Criteria in Solid Tumors version 1.1. Progression-free survival (PFS) and overall survival (OS) were calculated using the Kaplan-Meier method.

RESULTS

A total of 35 patients were included in this study. The median PFS (mPFS) for all patients was 5.43 months and the median OS (mOS) was 16 months. After rechallenge immunotherapy, only three patients achieved partial response, resulting in an overall response rate of 16.7%, and nine patients attained stable disease, resulting in a disease control rate of 66.7%. Patients who underwent rechallenge immunotherapy had shorter mPFS compared to chemotherapy (3.53 months vs. 6.00 months, P = 0.041). In addition, the incidence of Grade 3-4 treatment-related adverse events in these patients was 22.2%.

CONCLUSION

Rechallenge immunotherapy has poor efficacy in immunotolerant TC patients.

Avoiding misdiagnosis of multilocular thymic cysts as malignant tumors on computer tomography

This editorial provides insights from a case report by Sun et al published in the World Journal of Clinical Cases. The case report focuses on a case where a multilocular thymic cyst (MTC) was misdiagnosed as a thymic tumor, resulting in an unnecessary surgical procedure. Both MTCs and thymic tumors are rare conditions that heavily rely on radiological imaging for accurate diagnosis. However, the similarity in their imaging presentations can lead to misinterpretation, resulting in unnecessary surgical procedures. Due to the ongoing lack of comprehensive knowledge about MTCs and thymic tumors, we offer a summary of diagnostic techniques documented in recent literature and examine potential causes of misdiagnosis. When computer tomography (CT) values surpass 20 Hounsfield units and display comparable morphology, there is a risk of misdiagnosing MTCs as thymic tumors. Employing various differential diagnostic methods like biopsy, molecular biology, multi-slice CT, CT functional imaging, positron emission tomography/CT molecular functional imaging, magnetic resonance imaging and radiomics, proves advantageous in reducing clinical misdiagnosis. A deeper understanding of these conditions requires increased attention and exploration by healthcare providers. Moreover, the continued advancement and utilization of various diagnostic methods are expected to enhance precise diagnoses, provide appropriate treatment options, and improve the quality of life for patients with thymic tumors and MTCs in the future.

Sequential development of diffuse panbronchiolitis and myasthenia gravis after thymectomy for thymic neoplasm: a case report

BACKGROUND

Myasthenia gravis (MG) is the most common paraneoplastic disorder associated with thymic neoplasms. MG can develop after thymectomy, and this condition is referred to post-thymectomy myasthenia gravis (PTMG). Diffuse panbronchiolitis (DPB), is a rare form of bronchiolitis and is largely restricted to East Asia, has been reported in association with thymic neoplasms. Only three cases of combined MG and DPB have been reported in the literature.

CASE PRESENTATION

A 45-year-old Taiwanese woman presented to our hospital with productive cough, rhinorrhea, anosmia, ear fullness, shortness of breath, and weight loss. She had a history of thymoma, and she underwent thymectomy with adjuvant radiotherapy 7 years ago. Chest computed tomography scan revealed diffuse bronchitis and bronchiolitis. DPB was confirmed after video-assisted thoracoscopic surgery lung biopsy, and repeated sputum cultures grew Pseudomonas aeruginosa. She has been on long-term oral azithromycin therapy thereafter. Intravenous antipseudomonal antibiotics, inhaled amikacin, as well as oral levofloxacin were administered. Three months after DPB diagnosis, she developed ptosis, muscle weakness, and hypercapnia requiring the use of noninvasive positive pressure ventilation. MG was diagnosed based on the acetylcholine receptor antibody and repetitive stimulation test results. Her muscle weakness gradually improved after pyridostigmine and corticosteroid therapies. Oral corticosteroids could be tapered off ten months after the diagnosis of MG. She is currently maintained on azithromycin, pyridostigmine, and inhaled amikacin therapies, with intravenous antibiotics administered occasionally during hospitalizations for respiratory infections.

CONCLUSIONS

To our knowledge, this might be the first case report of sequential development of DPB followed by PTMG. The coexistence of these two disorders poses a therapeutic challenge for balancing infection control for DPB and immunosuppressant therapies for MG.

Trophoblast Cell Surface Antigen 2 Expression in Thymic Carcinoma: Brief Report

Introduction

Trophoblast cell surface antigen 2 (TROP2) is a transmembrane glycoprotein overexpressed in various cancer types. Although TROP2-targeting therapy is currently attracting attention, little is known about TROP2 expression in thymic carcinoma.

Methods

TROP2 gene expression in thymic epithelial tumors was analyzed using RNA-sequencing (RNA-seq) data for 122 cases obtained from The Cancer Genome Atlas. Immunohistochemistry (IHC) staining with anti-TROP2 antibody (SP295) was performed in 26 cases of thymic carcinoma tissues surgically resected at Juntendo University.

Results

RNA-seq data analysis from The Cancer Genome Atlas revealed that TACSTD2 (gene encoding TROP2) expression was significantly higher in thymic carcinoma than in thymoma (adjusted p = 6.64e-05). There was also a trend of increasing expression in the order of thymoma type B1, B2, B3, and thymic carcinoma. As for IHC in thymic carcinoma, TROP2 expression was localized to the membrane of cancer cells. Intensity 0, 1, and 2 was observed in six (23.1%), 11 (42.3%), and nine (34.6%) cases, respectively, leading to TROP2 positivity in 20 cases (76.9%). The median proportion of TROP2-positive tumor cells and the median H-score were 25.0% (range: 0%-100%) and 25.0 (range: 0-200), respectively. No relevant factors were identified in the analysis of TROP2 expression and patient background. Although not significant, high TROP2 expression (H-score ≥ 50) tended to be associated with shorter survival.

Conclusions

TROP2 expression in thymic carcinoma was confirmed by both RNA-seq and IHC, with high expression observed in IHC for intensity (76.9%) and proportion. TROP2 could be a potential target in thymic carcinoma.

Long-term prognosis in patients with thymoma combined with myasthenia gravis: a propensity score-matching analysis

Introduction

We aimed to assess the impact of myasthenia gravis (MG) on the long-term prognosis in patients with thymoma after surgery and identify related prognostic factors or predictors.

Methods

This retrospective observational study included 509 patients with thymoma (thymoma combined with MG [MG group] and thymoma alone [non-MG group]). Propensity score matching was performed to obtain comparable subsets of 96 patients in each group. A comparative analysis was conducted on various parameters.

Results

Before matching, the 10-year survival and recurrence-free survival rates in both groups were 93.8 and 98.4%, and 85.9 and 93.4%, respectively, with no statistically significant difference observed in the survival curves between the groups (p > 0.05). After propensity score matching, 96 matched pairs of patients from both groups were created. The 10-year survival and recurrence-free survival rates in these matched pairs were 96.9 and 97.7%, and 86.9 and 91.1%, respectively, with no statistical significance in the survival curves between the groups (p > 0.05). Univariate analysis of patients with thymoma postoperatively revealed that the World Health Organization histopathological classification, Masaoka-Koga stage, Tumor Node Metastasis stage, resection status, and postoperative adjuvant therapy were potentially associated with tumor recurrence after thymoma surgery. Multivariate analysis demonstrated that the Masaoka-Koga stage and postoperative adjuvant therapy independently predicted the risk of recurrence in patients with thymoma after surgery.

Conclusion

There was no difference in prognosis in patients with thymoma with or without MG. The Masaoka-Koga stage has emerged as an independent prognostic factor affecting recurrence-free survival in patients with thymoma, while postoperative adjuvant therapy represents a poor prognostic factor.

The Diagnostic and Prognostic Value of the Immune Checkpoint BGN in Thymoma

Thymoma is frequently correlated with various autoimmune diseases. However, unequivocal therapeutic targets for thymoma remain undefined, and the role of immune checkpoints in the development of thymoma-related autoimmune illnesses is unclear. We examined 39 thymoma samples and 44 normal control samples from the GEO database. Following batch correction, we identified 224 Differentially Expressed Genes (DEGs) using the Limma package. We employed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses to enrich for functional pathways of DEGs. We utilized a Protein-Protein Interaction (PPI) network to identify hub genes and determine their correlation with immune cell infiltration using CIBERSORT. Real-time quantitative polymerase chain reaction (RT-qPCR), western blot, and immunohistochemical staining were implemented to verify identified hub genes in vivo. Simultaneously, we evaluated the prognostic relevance of the hub gene using clinical data. We determined COL1A1, COL1A2, and BGN to be the central hub genes in thymoma. Validation via RT-qPCR, Western blot, and immunohistochemical staining established significant statistical divergence between thymoma tissue and the normal thymus for only BGN. Expression levels of BGN showed strong negative correlation with the infiltration level of B cells and CD4+ T cells, yet a significant positive correlation with the level of neutrophil infiltration. We found high immune infiltration levels of macrophages, NK cells, and Th1 cells in the thymoma microenvironment in patients with a high expression of BGN. Co-localization of BGN and macrophages within thymoma tissue was discerned via tissue staining. Clinical data dictated that thymoma patients exhibiting elevated BGN expression underwent longer hospital stays, longer lengths in intensive care units, greater hospitalization costs, and extended ventilator usage; our study, augmented by clinical information, recognized BGN as possessive of diagnostic and prognostic significance in thymoma through in silico and molecular verification experiments. Our findings offered an important objective for thymoma-treated autoimmune disease comprehension, supplemented by the strong association with immune infiltration.

Poor efficacy of immune checkpoint inhibitor treatment in advanced thymic carcinoma patients with liver metastases

Background

Although immune checkpoint inhibitor treatment for advanced thymic carcinoma exhibits promising efficacy, factors that affect the efficacy and prognosis, including metastases sites, remain uncertain.

Objectives

Our study aimed to investigate the determinants of survival among patients with advanced thymic carcinoma who underwent immunotherapy in real-world settings, with implications for clinical practice.

Designs

Different therapy regimens of immunotherapy were produced to analyze the influence of liver metastases on survival and prognosis for advanced thymic carcinoma patients.

Methods

Data for advanced thymic carcinoma patients receiving immunotherapy and their metastases sites were collected for analysis from seven different hospitals between January 2015 and January 2023. Progression-free survival (PFS) and overall survival (OS) analyses were performed using the Kaplan-Meier method. Cox analysis was used to evaluate factors influencing survival.

Results

The present study analyzed 136 advanced thymic carcinoma patients from seven different hospitals.The PFS for all patients receiving immunotherapy was 6.4 months, while the OS was 24.0 months. The objective response rate was different for patients with liver and non-liver metastases (11.9% versus 37.2%, p = 0.003). The disease control rate values were also different between the two groups (47.6% versus 80.9%, p = 0.037). The PFS for patients with liver metastases demonstrated poor immunotherapy efficacy compared to patients with non-liver metastases (3.0 versus 8.0 months, p < 0.0001). The OS was also significantly different between these two patient groups (16.1 versus 29.1 months, p = 0.009).

Conclusion

Immunotherapy had poor efficacy in advanced thymic carcinoma patients with liver metastases.

Li-Fraumeni Syndrome With Six Primary Tumors-Case Report

Li-Fraumeni syndrome (LFS) is a cancer predisposition syndrome associated with a high, lifetime risk of a broad spectrum of cancers caused by pathogenic germline TP53 mutations. Numerous different germline TP53 mutations have been associated with LFS, which has an exceptionally diverse clinical spectrum in terms of tumor type and age of onset. Our patient has developed six asynchronous tumors to date: a phyllode tumor of the breast, a pheochromocytoma, a rosette-forming glioneuronal tumor (RGNT), an adrenocortical carcinoma (ACC), a ductal carcinoma of the breast, and a thymoma. The occurrence of such a number of rare tumors is sporadic even among in the population of patients living with cancer predisposition syndromes. In this instance, the omission of pretest genetic counseling and thorough family tree analysis prior to selecting the test led to the oversight of an underlying TP53 likely pathogenic mutation (classified as Class 4). This emphasizes the necessity for such counseling to prevent overlooking crucial genetic information. Neglecting this step could have had profound implications on the patient's treatment, particularly considering the early onset and occurrence of multiple tumors, which typically raise suspicion of a hereditary component. The implications for family members must be considered.

MHD-Net: Memory-Aware Hetero-Modal Distillation Network for Thymic Epithelial Tumor Typing With Missing Pathology Modality

Fusing multi-modal radiology and pathology data with complementary information can improve the accuracy of tumor typing. However, collecting pathology data is difficult since it is high-cost and sometimes only obtainable after the surgery, which limits the application of multi-modal methods in diagnosis. To address this problem, we propose comprehensively learning multi-modal radiology-pathology data in training, and only using uni-modal radiology data in testing. Concretely, a Memory-aware Hetero-modal Distillation Network (MHD-Net) is proposed, which can distill well-learned multi-modal knowledge with the assistance of memory from the teacher to the student. In the teacher, to tackle the challenge in hetero-modal feature fusion, we propose a novel spatial-differentiated hetero-modal fusion module (SHFM) that models spatial-specific tumor information correlations across modalities. As only radiology data is accessible to the student, we store pathology features in the proposed contrast-boosted typing memory module (CTMM) that achieves type-wise memory updating and stage-wise contrastive memory boosting to ensure the effectiveness and generalization of memory items. In the student, to improve the cross-modal distillation, we propose a multi-stage memory-aware distillation (MMD) scheme that reads memory-aware pathology features from CTMM to remedy missing modal-specific information. Furthermore, we construct a Radiology-Pathology Thymic Epithelial Tumor (RPTET) dataset containing paired CT and WSI images with annotations. Experiments on the RPTET and CPTAC-LUAD datasets demonstrate that MHD-Net significantly improves tumor typing and outperforms existing multi-modal methods on missing modality situations.

Extracorporeal membrane oxygenation (ECMO) assisted huge mediastinal tumor resection combined with superior vena cava replacement: A case report and literature review

As to huge solid mediastinal tumor which direct compression or invasion of the superior/inferior vena cava (SVC/IVC), surgical resection remains the main lifesaving treatment. However, it would present formidable anesthetic challenges due to the extremely high risks of cardiorespiratory compromise, drastic hemodynamic fluctuations and death at all perioperative stages. Here, we report a case of huge anterior mediastinal tumor resection combined with SVC replacement under the assistance of venoarterial extracorporeal membrane oxygenation (VA ECMO), and stable hemodynamics were maintained as well as high internal jugular vein pressure being avoided during the operation procedure. He was weaned off ECMO successfully just after surgery and eventually discharged. No signs of postoperatively neurological complications occurred. Therefore, the use of ECMO assistance in huge mediastinal tumor resection combined with SVC replacement is feasible and safe, which may provide the possibility of surgical treatment for such patients and improve outcomes.

Autoimmunity in thymic epithelial tumors: a not yet clarified pathologic paradigm associated with several unmet clinical needs

Thymic epithelial tumors (TETs) are rare mediastinal cancers originating from the thymus, classified in two main histotypes: thymoma and thymic carcinoma (TC). TETs affect a primary lymphoid organ playing a critical role in keeping T-cell homeostasis and ensuring an adequate immunological tolerance against "self". In particular, thymomas and not TC are frequently associated with autoimmune diseases (ADs), with Myasthenia Gravis being the most common AD present in 30% of patients with thymoma. This comorbidity, in addition to negatively affecting the quality and duration of patients' life, reduces the spectrum of the available therapeutic options. Indeed, the presence of autoimmunity represents an exclusion criteria for the administration of the newest immunotherapeutic treatments with checkpoint inhibitors. The pathophysiological correlation between TETs and autoimmunity remains a mystery. Several studies have demonstrated the presence of a residual and active thymopoiesis in adult patients affected by thymomas, especially in mixed and lymphocytic-rich thymomas, currently known as type AB and B thymomas. The aim of this review is to provide the state of art in regard to the histological features of the different TET histotype, to the role of the different immune cells infiltrating tumor microenvironments and their impact in the break of central immunologic thymic tolerance in thymomas. We discuss here both cellular and molecular immunologic mechanisms inducing the onset of autoimmunity in TETs, limiting the portfolio of therapeutic strategies against TETs and greatly impacting the prognosis of associated autoimmune diseases.

Development and Validation of Contrast-Enhanced CT-Based Deep Transfer Learning and Combined Clinical-Radiomics Model to Discriminate Thymomas and Thymic Cysts: A Multicenter Study

RATIONALE AND OBJECTIVES

This study aims to evaluate the feasibility and effectiveness of deep transfer learning (DTL) and clinical-radiomics in differentiating thymoma from thymic cysts.

MATERIALS AND METHODS

Clinical and imaging data of 196 patients pathologically diagnosed with thymoma and thymic cysts were retrospectively collected from center 1. (training cohort: n = 137; internal validation cohort: n = 59). An independent external validation cohort comprised 68 thymoma and thymic cyst patients from center 2. Region of interest (ROI) delineation was performed on contrast-enhanced chest computed tomography (CT) images, and eight DTL models including Densenet 169, Mobilenet V2, Resnet 101, Resnet 18, Resnet 34, Resnet 50, Vgg 13, Vgg 16 were constructed. Radiomics features were extracted from the ROI on the CT images of thymoma and thymic cyst patients, and feature selection was performed using intra-observer correlation coefficient (ICC), Spearman correlation analysis, and least absolute shrinkage and selection operator (LASSO) algorithm. Univariate analysis and multivariable logistic regression (LR) were used to select clinical-radiological features. Six machine learning classifiers, including LR, support vector machine (SVM), k-nearest neighbors (KNN), Light Gradient Boosting Machine (LightGBM), Adaptive Boosting (AdaBoost), and Multilayer Perceptron (MLP), were used to construct Radiomics and Clinico-radiologic models. The selected features from the Radiomics and Clinico-radiologic models were fused to build a Combined model. Receiver operating characteristic curve (ROC), calibration curve, and decision curve analysis (DCA) were used to evaluate the discrimination, calibration, and clinical utility of the models, respectively. The Delong test was used to compare the AUC between different models. K-means clustering was used to subdivide the lesions of thymomas or thymic cysts into subregions, and traditional radiomics methods were used to extract features and compare the ability of Radiomics and DTL models to reflect intratumoral heterogeneity using correlation analysis.

RESULTS

The Densenet 169 based on DTL performed the best, with AUC of 0.933 (95% CI: 0.875-0.991) in the internal validation cohort and 0.962 (95% CI: 0.923-1.000) in the external validation cohort. The AdaBoost classifier achieved AUC of 0.965 (95% CI: 0.923-1.000) and 0.959 (95% CI: 0.919-1.000) in the internal and external validation cohorts, respectively, for the Radiomics model. The LightGBM classifier achieved AUC of 0.805 (95% CI: 0.690-0.920) and 0.839 (95% CI: 0.736-0.943) in the Clinico-radiologic model. The AUC of the Combined model in the internal and external validation cohorts was 0.933 (95% CI: 0.866-1.000) and 0.945 (95% CI: 0.897-0.994), respectively. The results of the Delong test showed that the Radiomics model, DTL model, and Combined model outperformed the Clinico-radiologic model in both internal and external validation cohorts (p-values were 0.002, 0.004, and 0.033 in the internal validation cohort, while in the external validation cohort, the p-values were 0.014, 0.006, and 0.015, respectively). But there was no statistical difference in performance among the three models (all p-values <0.05). Correlation analysis showed that radiomics performed better than DTL in quantifying intratumoral heterogeneity differences between thymoma and thymic cysts.

CONCLUSION

The developed DTL model and the Combined model based on radiomics and clinical-radiologic features achieved excellent diagnostic performance in differentiating thymic cysts from thymoma. They can serve as potential tools to assist clinical decision-making, particularly when endoscopic biopsy carries a high risk.

Acute mediastinal mass syndrome after surgical biopsy of a massive anterior mediastinal tumor: a case report

BACKGROUND

Mediastinal lymphatic tumors are relatively rare. The prognosis is poor but has improved due to recent advances in treatment strategies. Herein, we report a case of mediastinal lymphoma diagnosed using surgical biopsy, which was complicated by mediastinal mass syndrome due to general anesthesia.

CASE PRESENTATION

A 25-year-old man with cough, fever, dyspnea, and night sweats was transferred to our hospital for resection of a large anterior mediastinal tumor. Although his preoperative diagnosis was WHO type B1 thymoma, the clinical findings suggested a lymphoma. A repeat surgical biopsy was performed under general anesthesia. Immediately after extubation, the patient developed acute respiratory failure with hypolucency of the right lung field on chest radiography. He was reintubated immediately and was diagnosed with negative pressure pulmonary edema in the right lung. He was managed with positive-pressure ventilation and his respiratory distress resolved within 5 days. Pathological examination of surgical specimens confirmed the diagnosis of lymphoma.

CONCLUSION

Surgical biopsy is useful for the diagnosis of mediastinal tumors. However, the risk of perioperative mediastinal mass syndrome should be carefully assessed before administering general anesthesia.

Advanced thymic carcinoma with a hepatic metastasis treated with chemotherapy and staged resection

Thymic carcinoma is rare, with resulting treatment of patients with extrathoracic metastasis being on a case-by-case basis. We describe the management of a woman in her 70s with an incidentally discovered cystic hepatic lesion with confirmation of a solitary extrathoracic metastasis from a synchronous primary thymic carcinoma. Following chemotherapy and staged resection of the metastasis and the primary tumour, the patient remained free of disease on radiological surveillance 6 months postoperatively.

A Painless Right Anterior Neck Mass

A 58-year-old woman presents with a several-week history of a painless right-sided swelling on her anterior neck. What is your diagnosis?

Dexamethasone improves thymoma-associated myasthenia gravis via the AKT-mTOR pathway

Clinically, thymoma patients are often complicated with myasthenia gravis (MG). Dexamethasone, a glucocorticoid with anti-inflammatory effects, could be used as an immunosuppressant for thymoma-associated MG, but the mechanism of action remains to be explored. In this study, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, weighted gene co-expression network analysis (WGCNA) of potential targets was performed by screening the intersection targets of dexamethasone and thymoma-associated MG from the database. Furthermore, the key targets and core active components were identified by topological analysis of the protein-protein interaction (PPI) network. Molecular docking technology was applied to screen the complexes with stable binding of dexamethasone and core targets. Patients with thymoma were divided into two groups according to whether they received dexamethasone before operation, and immunohistochemistry and western blot were used to verify the selected target of dexamethasone in treating thymoma-associated MG. The results showed that the action pathway of dexamethasone on the disease was closely enriched to phosphatidylinositol 3-kinase (PI3K)-protein kinase B (PKB/AKT), mammalian target of rapamycin (mTOR) signaling pathways. The expressions of AKT1 and its downstream molecule mTOR in the thymoma microenvironment of thymoma-associated MG patients who did not receive dexamethasone before operation were higher than those in the group receiving dexamethasone before operation. This study demonstrates that dexamethasone can promote apoptosis through the AKT-mTOR pathway for the treatment of thymoma-associated MG, as validated by network pharmacology predictions and clinical specimen experiments, and can be verified by large-scale clinical trials in the future. This study also provides theoretical support and new research perspectives for this disease.

Comprehensive study of clinicopathological and immune cell infiltration and lactate dehydrogenase expression in patients with thymic epithelial tumours

BACKGROUND

Lactate dehydrogenase (LDH) has emerged as a promising biomarker for cancer. However, the current understanding of LDH and circulating LDH expression in thymic epithelial tumour (TET) is lacking.

METHODS

A comprehensive literature review and meta-analysis were performed to evaluate the clinical significance of circulating LDH levels in patients with TET. Circulating LDH levels were measured using a laboratory analyser (Cobas8000, Roche, Basel, Switzerland). The maximum standardised uptake value (SUVmax) was determined in patients who underwent whole-body 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). Multiplex immunohistochemistry (IHC) was performed using a commercially available kit (Opal 6-plex Detection Kit, Akoya Biosciences, Marlborough, MA, USA) and slide scanner (Slideview VS200, Olympus, Tokyo, Japan). All statistical analyses were performed using SPSS (IBM Corp., Armonk, NY, USA) and Prism version 9.0 (GraphPad Inc., San Diego, CA, USA). Differences with p < 0.05 were considered to be statistically significant.

RESULTS

Meta-analysis revealed that elevated circulating serum levels of LDH predicted poor prognosis in patients with TET. Circulating levels of LDH were analysed in the serum of 313 patients with TET and 87 with benign mediastinal mass. The mean circulating LDH level in patients with thymic carcinoma (TC) was significantly higher than that in those with thymoma (TM) and the benign group (p < 0.001). Expression levels of circulating LDH were significantly reduced in postoperative samples compared with that in preoperative samples (p < 0.05). Receiver operating characteristic (ROC) curve analysis for diagnosing TC yielded an area under the curve of 0.74, with a sensitivity of 54 % and specificity of 86 %. Furthermore, patients with TC exhibited higher 18F-FDG PET/CT SUVmax values compared to those with TM. Correlation analysis demonstrated a positive association between SUVmax values and circulating LDH levels. In addition, the percentages of LDH-positive cells in TC and type B1 TM tissues were higher than those in other subtypes of TM, and a significant positive correlation between the percentages of LDH-positive and CD20-positive cells was detected in patients with TET (p < 0.05).

CONCLUSION

Circulating serum LDH level may serve as a non-invasive biomarker for the diagnosis and prognosis of TET. The relationship between LDH expression and immune cell infiltration merits further regarding its application in companion diagnosis for immunotherapy.

Socioeconomic Factors Associated With Thymoma Survival in the United States

INTRODUCTION

The effects of socioeconomic factors on patients diagnosed with thymomas have not been previously studied. We propose these factors have an important association with survival. Thymoma is the most common tumor of the anterior mediastinum. Compared to other neoplasms which can integrate different therapeutic approaches for treatment, the most effective therapy for local and locally advanced thymoma is complete surgical resection. This study aimed to elaborate on socioeconomic variables and their potential effects on the survival outcomes in patients diagnosed with thymoma.

METHODS

Clinical data from the Surveillance, Epidemiology, and End Results 22 registry from 1975-2019 was used to define overall and cancer-specific survival of thymoma. The unadjusted analysis was followed by fitting a Cox proportional hazards model that included all variables assessed with Kaplan-Meier curves. An unadjusted Kaplan-Meier analysis was performed first comparing time to death by decade, age, race, ethnicity, sex, income, and region separately. The primary outcome was survival measured in months.

RESULTS

We identified 1821 patients aged 18 y or over from the Surveillance, Epidemiology, and End Results database with a thymoma diagnosis between the years 1975 and 2019. The demographic variables considered were age, race, ethnicity (Hispanic/non-Hispanic), sex (male/female), inflation-adjusted income in 2019 dollars, and community size. We observed a decrease in mortality from thymic neoplasm across the decades. For each subsequent year, mortality risk decreased by 3.5% (P <0.001). The mortality risk of older patients was significantly higher. Compared to the youngest group, the mortality risk was 52.8% higher in the 50-year-old to 65-year-old category (P = 0.021). The mortality risk was 339% times higher in the 65 + age group (P <0.001). Income may be associated with risk reduction. Patients making greater than $75,000 had a 40.1% lower mortality risk than those making less than $50,000 (P = 0.029). The survival rate categorized by race was similar between Blacks and Whites but tended to be higher for the Asian and Pacific Islander groups without reaching statistical significance (P = 0.12).

CONCLUSIONS

Medical advancements have improved the overall thymoma survival in the past four decades. Yet, demographic, and socioeconomic factors such as age, income, and race may also play a role.

Thymic Epithelial Tumor and Immune System: The Role of Immunotherapy

Thymic epithelial tumors (TETs) comprise a rare group of thoracic cancers, classified as thymomas and thymic carcinomas (TC). To date, chemotherapy is still the standard treatment for advanced disease. Unfortunately, few therapeutic options are available for relapsed/refractory tumors. Unlike other solid cancers, the development of targeted biologic and/or immunologic therapies in TETs remains in its nascent stages. Moreover, since the thymus plays a key role in the development of immune tolerance, thymic tumors have a unique biology, which can confer susceptibility to autoimmune diseases and ultimately influence the risk-benefit balance of immunotherapy, especially for patients with thymoma. Indeed, early results from single-arm studies have shown interesting clinical activity, albeit at a cost of a higher incidence of immune-related side effects. The lack of knowledge of the immune mechanisms associated with TETs and the absence of biomarkers predictive of response or toxicity to immunotherapy risk limiting the evolution of immunotherapeutic strategies for managing these rare tumors. The aim of this review is to summarize the existing literature about the thymus's immune biology and its association with autoimmune paraneoplastic diseases, as well as the results of the available studies with immune checkpoint inhibitors and cancer vaccines.

Genetic insights into thymic carcinomas and thymic neuroendocrine neoplasms denote prognosis signatures and pathways

BACKGROUND

Thymic carcinomas (TCs) and thymic neuroendocrine neoplasms (TNENs) are two aggressive subtypes of thymic malignancy. Traditional therapy for advanced TCs and TNENs has limited outcome. New genomic profiling of TCs and TNENs might provide insights that contribute to the development of new treatment approaches.

METHODS

We used gene panel sequencing technologies to investigate the genetic aberrations of 32 TC patients and 15 TNEN patients who underwent surgery at Shanghai Chest Hospital between 2015 and 2017. Patient samples were sequenced using a 324-gene platform with licensed technologies. In this study, we focused on clinically relevant genomic alterations (CRGAs), which are previously proven to be pathogenic alterations, to identify the pathology-specific mutational patterns, prognostic signatures of TCs and TNENs.

RESULTS

The mutational profiles between TCs and TNENs were diverse. The genetic alterations that ranked highest in TCs were in CDKN2A, TP53, ASXL1, CDKN2B, PIK3C2G, PTCH1, and ROS1 , while those in TNENs were in MEN1, MLL2, APC, RB1 , and TSC2 . Prognostic analysis showed that mutations of ROS1, CDKN2A, CDKN2B, BRAF, and BAP1 were significantly associated with worse outcomes in TC patients, and that mutation of ERBB2 indicated shortened disease-free survival (DFS) and overall survival (OS) in TNEN patients. Further investigation found that the prognosis-related genes were focused on signal pathways of cell cycle control, chromatin remodeling/DNA methylation, phosphoinositide 3-kinases (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR), and receptor tyrosine kinase (RTK)/RAS/mitogen-activated protein kinase (MAPK) signaling.

CONCLUSION

We profiled the mutational features of 47 Chinese patients with thymic malignancy of diverse pathologic phenotypes to uncover the integrated genomic landscape of these rare tumors, and identified the pathology-specific mutational patterns, prognostic signatures, and potential therapeutic targets for TCs and TNENs.

Deep learning-based radiomic nomogram to predict risk categorization of thymic epithelial tumors: A multicenter study

PURPOSE

The study was aimed to develop and evaluate a deep learning-based radiomics to predict the histological risk categorization of thymic epithelial tumors (TETs), which can be highly informative for patient treatment planning and prognostic assessment.

METHOD

A total of 681 patients with TETs from three independent hospitals were included and separated into derivation cohort and external test cohort. Handcrafted and deep learning features were extracted from preoperative contrast-enhanced CT images and selected to build three radiomics signatures (radiomics signature [Rad_Sig], deep learning signature [DL_Sig] and deep learning radiomics signature [DLR_Sig]) to predict risk categorization of TETs. A deep learning-based radiomic nomogram (DLRN) was then depicted to visualize the classification evaluation. The performance of predictive models was compared using the receiver operating characteristic and decision curve analysis (DCA).

RESULTS

Among three radiomics signatures, DLR_Sig demonstrated optimum performance with an AUC of 0.883 for the derivation cohort and 0.749 for the external test cohort. Combining DLR_Sig with age and gender, DLRN was depict and exhibited optimum performance among all radiomics models with an AUC of 0.965, accuracy of 0.911, sensitivity of 0.921 and specificity of 0.902 in the derivation cohort, and an AUC of 0.786, accuracy of 0.774, sensitivity of 0.778 and specificity of 0.771 in the external test cohort. The DCA showed that DLRN had greater clinical benefit than other radiomics signatures.

CONCLUSIONS

Our study developed and validated a DLRN to accurately predict the risk categorization of TETs, which has potential to facilitate individualized treatment and improve patient prognosis evaluation.

Changes and significance of serum AchR-Ab and CAE-Ab in patients with thymoma after thoracoscopic surgery

To probe into the changes and significance of serum acetylcholine receptor antibody (AchR-Ab) and citric acid extractive antibody (CAE-Ab) in patients with thymoma after thoracoscopic surgery (TS). The data of 50 patients with thymoma receiving TS in our hospital from February 2017 to February 2021 were selected for retrospective analysis. Serological testing was performed before and after surgery to determine serum AchR-Ab and CAE-Ab levels, the therapeutic effect was evaluated and the trend of serum AchR-Ab and CAE-Ab changes and their meanings were analyzed. Among 50 patients with thymoma after TS, 15 (30.0%) were in remission, 25 (50.0%) had improvement and 10 (20.0%) had no response to treatment. After treatment, the serum AchR-Ab and CAE-Ab levels of patients, which were remarkably lower than those before treatment (P < 0.001), were remarkably lower in the remission group than in the improvement group (P < 0.001) and remarkably lower in the improvement group than in the ineffective group (P < 0.001). The ordinal logistic regression analysis concluded that the levels of AchR-Ab and CAE-Ab were related to therapeutic effect, i.e. the lower the serum AchR-Ab and CAE-Ab levels, the better the therapeutic effect. TS can reduce the serum AchR-Ab and CAE-Ab levels in patients with thymoma, and serum AchR-Ab and CAE-Ab levels can reflect the therapeutic effect, providing reference value.

Prognosis of Concurrent Versus Sequential Chemo-Radiotherapy Induction Followed by Surgical Resection in Patients with Advanced Thymic Epithelial Tumors: A Retrospective Study

BACKGROUND

This study aimed to evaluate the prognosis of concurrent chemo-radiotherapy (CCRT) versus sequential chemo-radiotherapy (SCRT) induction followed by surgical resection in patients with advanced thymic epithelial tumors (TETs).

METHODS

This retrospective study included patients with advanced TETs who underwent CCRT or SCRT induction followed by surgical resection at the Second General Hospital of Guangdong Province between January 2008 and December 2019. The primary outcomes were induction response rate and surgical complete resection rate. The secondary outcomes were surgery combined resection, post-induction T staging, postoperative TNM staging, postoperative pathological tumor regression grade, progression-free survival (PFS) and overall survival (OS), and adverse events (AEs).

RESULTS

A total of 31 patients were included, 15 of whom received CCRT and the other 16 SCRT. The induction response rates were 80.0 and 62.5%, respectively, the post-induction step-down rates were 46.7 and 31.3%, respectively, and the post-induction R0 resection rates were 80.0 and 68.8%, respectively, without significant differences between CCRT and SCRT groups (all P > 0.05). The 5-year OS rate was 64.2 and 51.6%, respectively, and PFS was 42.3 and 21.4%, respectively, without significant differences between CCRT and SCRT groups (both P > 0.05). AEs in the hematologic system were significantly higher with CCRT compared with SCRT (P = 0.009).

CONCLUSIONS

Patients with advanced TETs might have a good prognosis with both CCRT and SCRT induction therapy, while SCRT induction may result in a lower probability of AEs in the hematologic system.

Differentiating invasive thymic epithelial tumors from mediastinal lung cancer using spectral CT parameters

PURPOSE

The purpose of the study was to explore the importance of quantitative characteristics of spectral CT between invasive thymic epithelial tumors (TETs) and mediastinal lung cancer.

METHODS

We analyzed 54 patients (28 with invasive TETs and 26 with mediastinal lung cancer) who underwent spectral CT. During the arterial and venous phase, we measured the CT70keV, effective atomic number (Zeff), iodine concentration (IC), and water concentration (WC) and calculated the slope of the spectral curve (K100keV). We compared the clinical findings and spectral CT parameters of both groups and performed receiver operating characteristic analysis to evaluate the diagnostic efficacy and the optimal cutoff values of the spectral CT parameters.

RESULTS

During the AP and VP, the CT70keV, Zeff, IC, and K100keV were significantly higher in patients with invasive TETs than those in patients with mediastinal lung cancer (p < 0.05). WC was not statistically significantly different between the two groups (p > 0.05). ROC curve analysis revealed that all quantitative parameters combined in the AP and VP provided the best diagnostic performance in identifying invasive TETs from mediastinal lung cancer (AUC = 0.88, p = 0.002, sensitivity = 0.89 and specificity = 0.77). The cutoff values in the AP for CT70keV, IC, Zeff, and K100keV to differentiate invasive TETs from mediastinal lung cancer were 75.55, 15.86, 8.45, and 1.71, respectively. The cutoff values in the VP for CT70keV, IC, Zeff, and K100keV to differentiate them were 67.06, 15.74, 8.50, and 1.81, respectively.

CONCLUSIONS

Spectral CT imaging has potential value in the differential diagnosis of invasive TETs and mediastinal lung cancer.

Diagnostic performance of radiomics model for preoperative risk categorization in thymic epithelial tumors: a systematic review and meta-analysis

BACKGROUND

Incidental thymus region masses during thoracic examinations are not uncommon. The clinician's decision-making for treatment largely depends on imaging findings. Due to the lack of specific indicators, it may be of great value to explore the role of radiomics in risk categorization of the thymic epithelial tumors (TETs).

METHODS

Four databases (PubMed, Web of Science, EMBASE and the Cochrane Library) were screened to identify eligible articles reporting radiomics models of diagnostic performance for risk categorization in TETs patients. The quality assessment of diagnostic accuracy studies 2 (QUADAS-2) and radiomics quality score (RQS) were used for methodological quality assessment. The pooled area under the receiver operating characteristic curve (AUC), sensitivity and specificity with their 95% confidence intervals were calculated.

RESULTS

A total of 2134 patients in 13 studies were included in this meta-analysis. The pooled AUC of 11 studies reporting high/low-risk histologic subtypes was 0.855 (95% CI, 0.817-0.893), while the pooled AUC of 4 studies differentiating stage classification was 0.826 (95% CI, 0.817-0.893). Meta-regression revealed no source of significant heterogeneity. Subgroup analysis demonstrated that the best diagnostic imaging was contrast enhanced computer tomography (CECT) with largest pooled AUC (0.873, 95% CI 0.832-0.914). Publication bias was found to be no significance by Deeks' funnel plot.

CONCLUSIONS

This present study shows promise for preoperative selection of high-risk TETs patients based on radiomics signatures with current available evidence. However, methodological quality in further studies still needs to be improved for feasibility confirmation and clinical application of radiomics-based models in predicting risk categorization of the thymic epithelial tumors.

Case Report: Paraneoplastic psoriasis in thymic carcinoma

Thymic carcinomas are exceedingly rare and very aggressive malignancies of the anterior mediastinum. While thymomas exhibit a high association with paraneoplastic syndromes, these phenomena are a rarity in thymic carcinomas. In general, acanthotic syndromes such as acroceratosis neoplastica and acanthosis nigricans maligna are commonly observed as paraneoplastic phenomena in patients with carcinomas. In contrast, psoriasis vulgaris, another acanthotic disease, rarely occurs as a paraneoplasia. We report the case of a 36-year-old patient with progressive thymic carcinoma (undifferentiated carcinoma, T3N2M1a) and paraneoplastic psoriasis occurring ten months before the initial diagnosis of the carcinoma. Over the course of the disease, new psoriatic flares heralded relapse or progression of the carcinoma. To our knowledge, this is the first reported case of paraneoplastic psoriasis in thymic carcinoma.

Diagnosis and therapy of myasthenia gravis-the patients' perspective: a cross-sectional study

The survey aimed to explore patients' perspectives with myasthenia gravis (MG) toward the diagnosis made and the therapy used to treat MG. The survey was conducted with a quantitative method, using the CAWI technique. A total of 321 people participated in the survey. More than half of the respondents (56.4%) had suffered from MG for less than 10 years. In three out of 10 cases (30.9%), the diagnosis of MG lasted 3 years or longer. The diagnostic delay was significantly longer in female respondents than in the males (p = 0.029). Cholinergic drugs were used in 92.9% of cases initially, and as maintenance therapy in 84.3% of cases. Corticosteroids were used in initiating therapy (45.8%) and as maintenance therapy (46.4%). One in four respondents (25.5%) reported experiencing very strong and strong side effects after using steroids. The side effects from steroid therapy very strong or strong affected overall physical health in 55.9% of respondents, very strong or strong affected self-acceptance in 52%, to a very large or large extent on mental health in 47.1%, and to a very strong or strong extent influenced the performance of daily activities in 28.2%. More than half of the respondents (57.0%) had had a thymectomy. Seven out of 10 respondents (72.0%) declared that the therapy they were on at the time of the survey allowed them (to varying degrees) to control their course of MG. Low therapy acceptance and less well controlled MG was associated with a preference for non-tablet therapies (p = 0.045). Regular follow-up and cooperation with the specialist health care system should improve MG symptoms, activities of daily living, and quality of life.

Characterization of cancer subtypes associated with clinical outcomes by multi-omics integrative clustering

Cancer patients show heterogeneous phenotypes and very different outcomes and responses even to common treatments, such as standard chemotherapy. This state-of-affairs has motivated the need for the comprehensive characterization of cancer phenotypes and fueled the generation of large omics datasets, comprising multiple omics data reported for the same patients, which might now allow us to start deciphering cancer heterogeneity and implement personalized therapeutic strategies. In this work, we performed the analysis of four cancer types obtained from the latest efforts by The Cancer Genome Atlas, for which seven distinct omics data were available for each patient, in addition to curated clinical outcomes. We performed a uniform pipeline for raw data preprocessing and adopted the Cancer Integration via MultIkernel LeaRning (CIMLR) integrative clustering method to extract cancer subtypes. We then systematically review the discovered clusters for the considered cancer types, highlighting novel associations between the different omics and prognosis.

Early Postoperative Results after Thymectomy for Thymic Cancer: A Single-Institution Experience

BACKGROUND

Surgery for thymic cancers is considered the key of curative treatment. Preoperative patients' characteristics and intraoperative features might influence postoperative outcome. We aim to verify short-term outcomes and possible risk factors for complications after thymectomy.

METHODS

We retrospectively investigated patients undergoing surgery for thymoma or thymic carcinoma in the period between January 1, 2008, and December 31, 2021, in our department. Preoperative features, surgical technique (open, bilateral VATS, RATS), intraoperative characteristics and incidence of postoperative complications (PC) were analyzed.

RESULTS

We included in the study 138 patients. Open surgery was performed in 76 patients (55.1%), in 36 VATS (26.1%) and in 26 RATS (36.1%). Resection of one or more adjacent organs due to neoplastic infiltration was required in 25 patients. PC appeared in 25 patients (52% Clavien-Dindo grade I, 12% grade IVa). Open surgery had a higher incidence of PC (p < 0.001), longer postoperative in-hospital stay (p = 0.045) and larger neoplasm (p = 0.006). PC were significant related to pulmonary resection (p = 0.006), phrenic nerve resection (p = 0.029), resection of more than one organ (p = 0.009) and open surgery (p = 0.001), but only extended surgery of more organs was confirmed as independent prognostic factor for PC (p = 0.0013). Patients with preoperative myasthenia symptoms have a trend toward stage IVa complications (p = 0.065). No differences were observed between outcomes of VATS and RATS.

CONCLUSIONS

Extended resections are related to a higher incidence of PC, while VATS and RATS guarantee a lower incidence of PC and shorter postoperative stay even in patients that require extended resections. Symptomatic myasthenia patients might have a higher risk toward more severe complications.

Ultrahigh-performance liquid chromatography-high-resolution mass spectrometry-based plasma metabolomics study of thymoma and thymic hyperplasia

RATIONALE

Thymoma is a rare malignant tumor but it is the most common primary tumor of the anterior mediastinum. The current imaging methods for thymoma screening suffer from false positive rate problems, and thymoma pathogenesis remains elusive. Study of thymoma metabolic characteristics could provide clues for improving the diagnosis and understanding the pathogenesis of thymoma.

METHODS

Metabolic profiling of plasma from thymoma and thymic hyperplasia patients was performed using ultrahigh-performance liquid chromatography combined with high-resolution mass spectrometry in both positive and negative ionization modes. After pre- and post-processing, the dataset was divided into three age groups and statistical analysis was performed to select differential metabolites of thymoma. For feature identification, experimental tandem mass spectra were matched to those of databases and available chemical standards, and also manually annotated with plausible chemical structures to ensure high identification confidence.

RESULTS

A total of 47 differential metabolites were identified in thymoma. Significantly higher levels of histidine, sphinganine 1-phosphate, lactic acid dimer, phenylacetylglutamine, LPC (18:3) and LPC (16:1), and significantly lower levels of phenylalanine, indole-3-propionic acid (IPA), hippuric acid and mesobilirubinogen were associated with thymoma. Tryptophan level in thymoma-associated myasthenia gravis (TAMG) was significantly lower than that of the MG(-) group. IPA and hippuric acid abundances exhibited increasing trends from indolent to aggressive thymoma.

CONCLUSIONS

Our study revealed aberrant aromatic amino acid metabolism and fatty acid oxidation might be associated with thymoma. The identified unique metabolic characteristics of thymoma may provide valuable information for study of the molecular mechanism of thymoma pathogenesis, and improvement of diagnosis and discovery of new therapeutic strategies for thymoma.

Prognostic factors in patients with thymoma who underwent surgery

PURPOSE

Thymoma is the most common primary tumor in the anterior mediastinum. The prognostic factors of patients with thymoma still need to be clarified. In this study, we aimed to investigate the prognostic factors of patients with thymoma who received radical resection and establish the nomogram to predict the prognosis of these patients.

MATERIALS AND METHODS

Patients who underwent radical resection for thymoma with complete follow-up data between 2005 and 2021 were enrolled. Their clinicopathological characteristics and treatment methods were retrospectively analyzed. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method and compared by the log-rank test. Univariate and multivariate Cox proportional hazards regression analyses were performed to identify the independent prognostic factors. According to the results of the univariate analysis in the Cox regression model, the predictive nomograms were created.

RESULTS

A total of 137 patients with thymoma were enrolled. With a median follow-up of 52 months, the 5-year and 10-year PFS rates were 79.5% and 68.1%, respectively. The 5-year and 10-year OS rates were 88.4% and 73.1%, respectively. Smoking status (P = 0.022) and tumor size (P = 0.039) were identified as independent prognostic factors for PFS. Multivariate analysis showed that a high level of neutrophils (P = 0.040) was independently associated with OS. The nomogram showed that the World Health Organization (WHO) histological classification contributed more to the risk of recurrence than other factors. Neutrophil count was the most important predictor of OS in patients with thymoma.

CONCLUSION

Smoking status and tumor size are risk factors for PFS in patients with thymoma. A high level of neutrophils is an independent prognostic factor for OS. The nomograms developed in this study accurately predict PFS and OS rates at 5 and 10 years in patients with thymoma based on individual characteristics.

Non-ST-segment elevation myocardial infarction with non-obstructive coronary arteries due to a type-A thymoma: A case report

Introduction

Myocardial infarction with non-obstructive coronary arteries (MINOCA) has become an increasingly recognized subgroup in patients with acute myocardial infarction, with a recent cohort study reporting a prevalence of 8.8%. This report describes a patient who presented with non-ST-segment elevation myocardial infarction (NSTEMI) due to an incidental anterior mediastinal mass.

Case presentation

An 80-year-old woman presented to our emergency department with a chief complaint of progressive shortness of breath associated with retrosternal chest pain for one day duration. Computed tomography (CT) angiogram of the chest was conducted, which revealed an anterior mediastinal mass. Upon admission, the patient developed an acute episode of recurrent severe chest pain, which was diagnosed as an NSTEMI. Emergent cardiac catheterization was performed because of unstable vital signs; however, the results showed no evidence of atherosclerotic changes in the major coronary arteries, compatible with the diagnosis of MINOCA. The mediastinal mass was later confirmed to be a type A thymoma on CT-guided biopsy.

Conclusion

Myocardial infarction in patent coronary arteries due to an anterior mediastinal mass is rare. Further studies are needed to standardize the diagnosis and management protocols for the potential etiologies of MINOCA.

A case-report of the unprovoked thrombotic event in a patient with thymoma and severe FVII deficiency

BACKGROUND

Factor VII deficiency is a rare bleeding disorder caused by a deficiency of clotting factor VII. However, there have been some case reports of venous thrombosis in patients with factor VII deficiency, especially underlying the prothrombotic risk factors exposure. Patients with factor VII deficiency require special considerations before undergoing surgery to minimize the risk of bleeding or thrombogenesis.

CASE PRESENTATION

Here, we described a patient with early-stage thymoma and severe factor VII deficiency who experienced an unprovoked thrombotic episode before thymectomy and a fatal thrombotic event after surgery. By adopting gene screening, a reported homozygous F7 mutation (p.His408Gln) and a novel heterozygous PROS1 mutation (p.Pro147Ala) were identified. The former resulted in severe factor VII deficiency but did not protect against thrombosis, and the latter was correlated with normal expression and cofactor activities of protein S through the thrombin generation test. The perioperative infusion of recombinant factor VII concentrate and the absence of antithrombotic prophylaxis may collectively contribute to her fatal thrombotic event after surgery.

CONCLUSIONS

For the patients with severe factor VII deficiency undergoing surgery, uniform replacement therapy may not be recommended, and antithrombotic prophylaxis should be used in the case with thrombotic history to minimize the risk of bleeding and thrombogenesis.

Immune checkpoint inhibitor sintilimab-induced lethal myocarditis overlapping with myasthenia gravis in thymoma patient: A case report

RATIONALE

Immune checkpoint inhibitors have been extensively used and significantly improved the clinical outcomes in multiple types of cancer. But the immune-related adverse events occur frequently, particularly in thymoma. The cardiac immune-related adverse, which is relatively rare but fatal, have been increasing reported.

PATIENT CONCERNS

A 45-year-old thymoma patient was admitted to our hospital after receiving anti-programmed cell death-1 treatment with sintilimab 14 days later, accompanied by abdominal pain, intermittent chest tightness and dizziness.

DIAGNOSES

The laboratory tests revealed elevated serum troponin I. Electrocardiogram reported the prolongation of QTc interval. Echocardiography showed small amount of pericardial effusion, a left ventricular ejection fraction of 71%. Coronary artery computed tomography angiography revealed localized noncalcified plaque in the middle of the left anterior descending artery and mild stenosis of the lumen. Enhanced computed tomography scanning of the whole abdomen showed no abnormal signs in the parenchyma organs. Combining the results of the examinations, the Immune checkpoint inhibitor induced myocarditis was diagnosed.

INTERVENTIONS

The patient was treated with glucocorticoids (120 mg/day, IV, methylprednisolone) within 24 hours of admission. Seven days later, the patient experienced tachy ventricular arrhythmia and cardiogenic shock and was transferred to intensive care unit after electrical cardioversion, tracheal intubation and cardiopulmonary resuscitation. Intravenous immunoglobulin therapy at 25 g/day was given and methylprednisolone was reduced to 40 mg/day for the next 3 days. Intravenous esmolol and lidocaine were used for correcting arrhythmias. Ventilator positive pressure ventilation was used for respiratory support. She was administrated with plasmapheresis when the electrocardiogram monitoring showed ventricular arrhythmia storms.

OUTCOME

The patient progressed to ventricular arrhythmia storms and cardiac failure, which eventually resulted in death.

LESSONS

The case aims to raise awareness of immune-mediated cardiotoxicity and bring thoughts to the prospects of immunotherapy in thymoma.

Conventional and radiomic features to predict pathology in the preoperative assessment of anterior mediastinal masses

OBJECTIVES

The aim of this study was to differentiate benign from malignant tumors in the anterior mediastinum based on computed tomography (CT) imaging characteristics, which could be useful in preoperative planning. Additionally, our secondary aim was to differentiate thymoma from thymic carcinoma, which could guide the use of neoadjuvant therapy.

MATERIALS AND METHODS

Patients referred for thymectomy were retrospectively selected from our database. Twenty-five conventional characteristics were evaluated by visual analysis, and 101 radiomic features were extracted from each CT. In the step of model training, we applied support vector machines to train classification models. Model performance was assessed using the area under the receiver operating curves (AUC).

RESULTS

Our final study sample comprised 239 patients, 59 (24.7 %) with benign mediastinal lesions and 180 (75.3 %) with malignant thymic tumors. Among the malignant masses, there were 140 (58.6 %) thymomas, 23 (9.6 %) thymic carcinomas, and 17 (7.1 %) non-thymic lesions. For the benign versus malignant differentiation, the model that integrated both conventional and radiomic features achieved the highest diagnostic performance (AUC = 0.715), in comparison to the conventional (AUC = 0.605) and radiomic-only (AUC = 0.678) models. Similarly, regarding thymoma versus thymic carcinoma differentiation, the model that integrated both conventional and radiomic features also achieved the highest diagnostic performance (AUC = 0.810), in comparison to the conventional (AUC = 0.558) and radiomic-only (AUC = 0.774) models.

CONCLUSION

CT-based conventional and radiomic features with machine learning analysis could be useful for predicting pathologic diagnoses of anterior mediastinal masses. The diagnostic performance was moderate for differentiating benign from malignant lesions and good for differentiating thymomas from thymic carcinomas. The best diagnostic performance was achieved when both conventional and radiomic features were integrated in the machine learning algorithms.

Brief Report: High Levels of CD47 Expression in Thymic Epithelial Tumors

Introduction

CD47 is a tumor antigen that inhibits phagocytosis leading to immune evasion. Anti-CD47 therapy is a promising new immunotherapy across numerous tumor types, but it has not been tested in thymic epithelial tumors (TETs): thymomas and thymic carcinomas. TETs are rare tumors that are difficult to treat, especially with programmed cell death protein 1/programmed death-ligand 1 checkpoint inhibitors, owing to the excessive rates of immune-related adverse events. This study investigated the levels of CD47 expression in TETs to explore the possibility of anti-CD47 therapy.

Methods

A total of 67 thymic tumors (63 thymomas and 4 thymic carcinomas) and 14 benign thymus controls and their clinical data were included. Samples were stained for CD47 expression (rabbit monoclonal antibody SP279, Abcam, Waltham, MA) and scored for both intensity and H-score (intensity multiplied by the percentage of tumor involved). Intensity was defined as follows: 0 = none, 1 = weak, 2 = moderate, and 3 = strong. H-scores ranged from 0 to 300. Samples with an intensity score below 2 or an H-score below 150 were considered CD47low, whereas the rest were CD47high.

Results

Compared with normal thymic tissues, TETs were more frequently CD47 positive and had significantly higher levels of CD47 expression. CD47 was positive in 79.1% of TETs compared with 57.1% of normal thymus. The level of CD47 expression was 16-fold higher in TETs (mean H-score 75.0 versus 4.6, p = 0.003). Multivariate analysis adjusted for age, sex, stage, resection status, and performance status revealed that CD47-high tumors were highly correlated with WHO histology type (p = 0.028). The most frequent CD47high tumors, in contrast to CD47low tumors, were types A (28.6% versus 7.5%) and AB (57.1% versus 13.2%), and the least frequent were B1 (7.1% versus 24.5%), B2 (0% versus 35.8%), B3 (7.1% versus 11.3%), and C (0% versus 7.5%).

Conclusions

In contrast to normal thymus, TETs had significantly higher levels of CD47 expression. Tumor samples with high CD47 expression were mostly WHO types A and AB. This is the first study to explore CD47 expression in thymic cancers and lends support for ongoing investigation of anti-CD47 macrophage checkpoint inhibitor therapy in these tumors.

Prognostic value of preoperative chemotherapy for thymic epithelial tumors: A propensity-matched analysis based on the SEER database

Background

The aim of this study was to assess the impact of preoperative chemotherapy on long-term survival (≥1 month) in patients with thymic epithelial tumors (TETs) and conditions suitable for chemotherapy using data from surveillance, epidemiology, and end-result databases.

Methods

This retrospective study controlled for confounding factors by propensity score matching (PSM), analyzed overall survival (OS) and cancer-specific survival (CSS) by Kaplan-Meier methods, and analyzed factors affecting the prognosis of patients undergoing surgery for thymic epithelial tumors by univariate and multifactorial Cox regression.

Results

A total of 2,451 patients who underwent surgery for TETs were identified from the Surveillance, Epidemiology, and End Results database. Preoperative chemotherapy significantly improved OS and CSS in patients with stage III/IV TETs compared to patients without preoperative chemotherapy. Subgroup analysis showed that patients younger than 60 years of age with TETs, patients with thymic carcinoma, and patients with TETs with multiple cancers were more likely to benefit from preoperative chemotherapy.

Conclusion

This study found that preoperative chemotherapy is a viable option for advanced thymoma with favorable overall and cancer-specific survival rates, but patient history and physical condition should be fully considered in conjunction with diagnostic imaging findings to assess patient tolerance to chemotherapy.

Molecular genetic characteristics of thymic epithelial tumors with distinct histological subtypes

BACKGROUND

Due to the low incidence and histological heterogeneity, the molecular features and underlying carcinogenic mechanisms of thymic epithelial tumors (TETs) are yet to be fully elucidated, especially for different subtypes of TETs.

METHODS

Tumor tissue samples of 43 TETs with distinct histological subtypes were collected. We analyzed the molecular characteristics in different subtypes based on whole exome sequencing data.

RESULTS

The mutational profiles of the different subtypes of TETs varied. Compared with thymomas, thymic carcinomas (TCs) had a higher mutation frequency of MYO16 (33% vs. 3%, p = 0.024) and a lower frequency of ZNF729 mutations (0% vs. 35%, p = 0.044). No significant difference was observed in the median tumor mutation burden across different subtypes. The value of copy number variation burden, weighted genome instability index, and the number of amplified segments were all higher in TCs than thymomas, and they also tended to be higher in B3 thymoma than in non-B3 thymomas, while they had no significant differences between B3 thymoma and TCs. Clustering analyses revealed that Wnt, MAPK, Hedgehog, AMPK, and cell junction assembly signaling pathways were exclusively enriched in non-B3 thymomas, lysine degradation pathway in B3 thymoma, and extracellular matrix-receptor (ECM-receptor) interaction, positive regulation of cell cycle process, and activation of innate immune response pathways in TCs.

CONCLUSIONS

This study revealed distinct molecular landscapes of different subtypes of TETs, suggesting diverse pathogenesis of non-B3 thymomas, B3 thymomas, and TCs. Our findings warrant further validation in future large-scale studies and may provide a theoretical basis for potential personalized therapeutic strategies.

HNRNPA2B1 as a potential therapeutic target for thymic epithelial tumor recurrence: An integrative network analysis

Thymic epithelial tumors (TETs) are rare malignant tumors, and the molecular mechanisms of both primary and recurrent TETs are poorly understood. Here we established comprehensive proteomic signatures of 15 tumors (5 recurrent and 10 non-recurrent) and 15 pair wised tumor adjacent normal tissues. We then proposed an integrative network approach for studying the proteomics data by constructing protein-protein interaction networks based on differentially expressed proteins and a machine learning-based score, followed by network modular analysis, functional enrichment annotation and shortest path inference analysis. Network modular analysis revealed that primary and recurrent TETs shared certain common molecular mechanisms, including a spliceosome module consisting of RNA splicing and RNA processing, but the recurrent TET was specifically related to the ribosome pathway. Applying the shortest path inference to the collected seed gene module identified that the ribonucleoprotein hnRNPA2B1 probably serves as a potential target for recurrent TET therapy. The drug repositioning combined molecular dynamics simulations suggested that the compound ergotamine could potentially act as a repurposing drug to treat recurrent TETs by targeting hnRNPA2B1. Our study demonstrates the value of integrative network analysis to understand proteotype robustness and its relationships with genotype, and provides hits for further research on cancer therapeutics.