The clinical features, diagnosis and management of recurrent thymoma

Survival Outcome After Surgery in Patients With Thymoma Distant Recurrence

OBJECTIVE

The aim of this study is to describe characteristics and survival outcome of patients who underwent surgical treatment for distant thymoma relapse according to the definition of the International Thymic Malignancy Interest Group.

METHODS

Data of patients affected by thymoma recurrence from four different institutions were collected and retrospectively reviewed. Patients with locoregional metastases who underwent nonsurgical therapies and with incomplete data on follow-up were excluded. According to the International Thymic Malignancy Interest Group distant recurrence definition, patients with recurrence due to hematogenic localization were included. Clinical and pathologic characteristics were described using descriptive statistics, whereas survival outcome was calculated using Kaplan-Meier curves and Cox regression analysis.

RESULTS

The analysis was conducted on 40 patients. A single localization was present in 13 patients, the relapse was intrathoracic in 28 cases (70%), and lung involvement was found in 26 cases. The liver was operated in seven cases, whereas other kinds of abdominal involvement were detected in eight cases. Adjuvant treatment was administered in 22 cases (55%).Five- and 10-year overall survival (OS) were 67% and 30%, respectively. Univariable analysis identified as significant favorable factor a low-grade histology (A, B1, B2): five-year OS at 92.3% versus 53.3% in high-grade (B3-C) (p = 0.035). Site of recurrence and number of localization did not influence the prognosis, but in patients with adjuvant therapy administration, there was a survival advantage also if not statistically significant: five-year OS 84.8% versus 54.5% in patients without adjuvant therapy (p = 0.101).Multivariable analysis confirmed as independent prognostic factor low-grade histology: hazard ratio = 0.176, 95% confidence interval 0.042-0.744, p = 0.018.

CONCLUSIONS

Our study revealed a good survival outcome in patients who underwent surgery for distant thymoma recurrence, independently from the number and site of the relapse localization. Patients with A, B1, or B2 histology presented a significantly better survival than patients with B3-C.

Thymoma: An Overview

Thymomas are considered one of the most prevalent types of mediastinal epithelial tumors, which frequently develop in the anterior mediastinum. Due to their rarity, these tumors' nomenclature, classification, and staging are likely to be the subject of debate and argument for most expert pathologists. Furthermore, the significance of thymoma histologic classifications have been debated over the past twenty years. While certain advocates argue that staging at the time of diagnosis is more significant, others believe that histologic subtyping has a significant impact on how patients behave clinically. In this review, we will focus on some of the challenges that diagnostic surgical pathologists may experience while evaluating the histopathology of thymomas and staging these tumors. We will additionally glance over the clinical characteristics of these distinct tumors and the current management strategy.

Anterior mediastinal tumor surgery applying single-port thoracoscopy using the subxiphoid approach

Background

This study aims to investigate the effectiveness of application of single-port thoracoscopy using the subxiphoid approach in anterior mediastinal tumor surgery.

Methods

Between June 2014 and June 2016, a total of 108 patients (59 males, 49 females; mean age: 64.9±7.5 years; range, 45 to 79 years) with anterior mediastinal tumors were randomized into subxiphoid (experimental) or right chest (control) groups. Single-port thoracoscopy using the subxiphoid approach was performed in the subxiphoid group, while thoracoscopy using the right thoracic approach was performed in the control group. Preand postoperative pain stress indicators, Visual Analog Scale scores, quality of life scores, postoperative tumor recurrence, and five-year survival rates were compared between the groups.

Results

There were no mortality or serious complications in either group. The mean Visual Analog Scale pain scores on postoperative Days 1 and 7 were 6.5±0.8 and 2.9±0.8 in the subxiphoid group, respectively, compared to 7.2±0.8 and 3.4±0.8 in the control group (p<0.05 for all), respectively. The mean quality of life scores on postoperative Days 1 and 7 were 81.5±5.0 and 79.3±7.7, respectively, in the subxiphoid group compared to 72.4±4.3 and 71.3±4.8 in the control group, respectively (p<0.05 for all). Postoperative pain and pain mediator indexes were lower in the subxiphoid group (p<0.05 for all). The postoperative tumor recurrence rates were 3.70% and 20.37% in the subxiphoid and control groups, respectively (p=0.008). The five-year survival rates were 85.2% and 63.0% in the subxiphoid and control groups, respectively (p=0.008).

Conclusion

Single-port thoracoscopy using the subxiphoid approach is technically feasible, safe, and effective in performing surgery for anterior mediastinal tumors with an intact capsule and a tumor diameter of ≤5 cm.

Predicting the Risk of Thymic Tumors Using Texture Analysis of Contrast-Enhanced Chest Computed Tomography

OBJECTIVE

This study aimed to explore the value of contrast-enhanced computed tomography texture features for predicting the risk of malignant thymic epithelial tumor.

METHODS

Data of 97 patients with pathologically confirmed thymic epithelial tumors treated at in our hospital from March 2015 to October 2021 were retrospectively analyzed. Based on the World Health Organization classification of thymic epithelial tumors, patients were divided into a high-risk group (types B2, B3, and C; n = 45) and a low-risk group (types A, AB, and B1; n = 52). Texture analysis was performed using a first-order, gray-level histogram method. Six features were evaluated: mean, variance, skewness, kurtosis, energy, and entropy. The association between contrast-enhanced computed tomography texture features and the risk of malignancy in thymic epithelial tumors was analyzed. The predictive thresholds of predictive texture features were determined by receiver operating characteristics analysis.

RESULTS

The mean, skewness, and entropy were significantly greater in the high-risk group than in the low-risk group (P < 0.05); however, variance, kurtosis, and energy were comparable in the two groups (P > 0.05). The area under curve of mean, skewness, and entropy was 0.670, 0.760, and 0.880, respectively. The optimal cutoff value of entropy for predicting risk of malignancy was 7.74, with sensitivity, specificity, and accuracy of 80.0%, 80.0%, and 75%, respectively.

CONCLUSIONS

Contrast-enhanced computed tomography texture features, especially entropy, may be a useful tool to predict the risk of malignancy in thymic epithelial tumors.

MC-ViT: Multi-path cross-scale vision transformer for thymoma histopathology whole slide image typing

OBJECTIVES

Accurate histological typing plays an important role in diagnosing thymoma or thymic carcinoma (TC) and predicting the corresponding prognosis. In this paper, we develop and validate a deep learning-based thymoma typing method for hematoxylin & eosin (H&E)-stained whole slide images (WSIs), which provides useful histopathology information from patients to assist doctors for better diagnosing thymoma or TC.

METHODS

We propose a multi-path cross-scale vision transformer (MC-ViT), which first uses the cross attentive scale-aware transformer (CAST) to classify the pathological information related to thymoma, and then uses such pathological information priors to assist the WSIs transformer (WT) for thymoma typing. To make full use of the multi-scale (10×, 20×, and 40×) information inherent in a WSI, CAST not only employs parallel multi-path to capture different receptive field features from multi-scale WSI inputs, but also introduces the cross-correlation attention module (CAM) to aggregate multi-scale features to achieve cross-scale spatial information complementarity. After that, WT can effectively convert full-scale WSIs into 1D feature matrices with pathological information labels to improve the efficiency and accuracy of thymoma typing.

RESULTS

We construct a large-scale thymoma histopathology WSI (THW) dataset and annotate corresponding pathological information and thymoma typing labels. The proposed MC-ViT achieves the Top-1 accuracy of 0.939 and 0.951 in pathological information classification and thymoma typing, respectively. Moreover, the quantitative and statistical experiments on the THW dataset also demonstrate that our pipeline performs favorably against the existing classical convolutional neural networks, vision transformers, and deep learning-based medical image classification methods.

CONCLUSION

This paper demonstrates that comprehensively utilizing the pathological information contained in multi-scale WSIs is feasible for thymoma typing and achieves clinically acceptable performance. Specifically, the proposed MC-ViT can well predict pathological information classes as well as thymoma types, which show the application potential to the diagnosis of thymoma and TC and may assist doctors in improving diagnosis efficiency and accuracy.

Seronegative autoimmune diseases: A challenging diagnosis

Autoimmune diseases (AID) are increasingly prevalent conditions which comprise more than 100 distinct clinical entities that are responsible for a great disease burden worldwide. The early recognition of these diseases is key for preventing their complications and for tailoring proper management. In most cases, autoantibodies, regardless of their potential pathogenetic role, can be detected in the serum of patients with AID, helping clinicians in making a definitive diagnosis and allowing screening strategies for early -and sometimes pre-clinical- diagnosis. Despite their undoubted crucial role, in a minority of cases, patients with AID may not show any autoantibody, a condition that is referred to as seronegative AID. Suboptimal accuracy of the available laboratory tests, antibody absorption, immunosuppressive therapy, immunodeficiencies, antigen exhaustion, and immunosenescence are the main possible determinants of seronegative AID. Indeed, in seronegative AID, the diagnosis is more challenging and must rely on clinical features and on other available tests, often including histopathological evaluation and radiological diagnostic tests. In this review, we critically dissect, in a narrative fashion, the possible causes of seronegativity, as well as the diagnostic and management implications, in several AID including autoimmune gastritis, celiac disease, autoimmune liver disease, rheumatoid arthritis, autoimmune encephalitis, myasthenia gravis, Sjögren's syndrome, antiphospholipid syndrome, and autoimmune thyroid diseases.

Pure White Cell Aplasia and Immune Thrombocytopenia after Thymoma Resection: A Case Report and Review of the Literature

We report a case of pure white cell aplasia (PWCA) postthymoma resection in a 74-year-old male presenting with a 2-week history of fevers, night sweats, and severe febrile neutropenia. His pure white cell aplasia was treated with intravenous immunoglobulin (IVIg), granulocyte colony-stimulating factor (G-CSF), prednisone, and cyclosporine with a mixed response. He also developed immune thrombocytopenia, which responded well to a short course of eltrombopag. With continued cyclosporine treatment, his platelet counts were stable after stopping eltrombopag. The patient's cyclosporine treatment was complicated by renal failure, resulting in cessation of cyclosporine. His PWCA and immune thrombocytopenia significantly worsened after stopping cyclosporine, and unfortunately, he died from multiorgan failure and sepsis.

Robotic thymectomy for thymomas: a retrospective follow-up study in the Netherlands

BACKGROUND

The Maastricht University Medical Center+ (MUMC+) is a Dutch center of expertise, appointed by the Netherlands Federation of University Medical Centres (NFU), for the treatment of thymomas. The aim of this study was to investigate the long-term oncological-, surgical-, and neurological outcomes of all patients who underwent a robotic thymectomy for a thymoma at the MUMC+.

METHODS

We retrospectively analyzed the clinical-pathological data of all consecutive patients with a thymoma who underwent robotic thymectomy using the DaVinci® Robotic System at the MUMC+ between April 2004 and December 2018. Follow-up data were collected from 60 referring Dutch hospitals.

RESULTS

In total, 398 robotic thymectomies were performed and 130 thymomas (32.7%) were found. Median follow-up time, procedure time and hospitalization were 46 months, 116 minutes and 3 days, respectively. In 8.4% of the patients a conversion was performed and in 20.8% a complication was registered. The majority of myasthenic patients with a thymoma went into remission, mostly within 12 to 24 months after thymectomy (81.0%). No statistical difference was found in the number of complications, conversions, incomplete resections or deaths between patients with myasthenia gravis and nonmyasthenic patients. Thirty-six patients (27.7%) underwent postoperative radiotherapy. The recurrence rate was 9.1% and the five-year thymoma-related survival rate was 96.6% .

CONCLUSIONS

Robotic thymectomy was found to be safe and feasible in early-stage thymomas, most advanced-stage thymomas and thymomatous myasthenia gravis. A national guideline could contribute to the improvement of the oncological follow-up of thymic epithelial tumors in the Netherlands.

Diagnostic and prognostic value of FDG PET-CT in patients with suspected recurrent thymic epithelial tumors

This study aimed to evaluate the diagnostic and prognostic value of FDG PET/CT in patients with suspected recurrent thymic epithelial tumors (TETs). We retrospectively reviewed 83 patients with histopathologically proven TETs (50 thymomas; 33 thymic carcinomas) who underwent FDG PET/CT after surgery. The sensitivity and specificity of FDG PET/CT in detecting recurrence were calculated. The progression-free survival rate (PFS) was calculated by the Kaplan-Meier method. FDG PET/CT results were positive in 50 patients and negative in 33. Recurrent TETs were confirmed in 40 of 50 patients with positive PET/CT findings. The sensitivity and specificity of FDG PET/CT were 100% and 76.7%, respectively. Disease progression occurred in 28 patients during the follow-up. FDG PET/CT showed added prognostic value over the Masaoka stage and histopathology. Among patients with the same Masaoka stage, negative PET/CT was significantly associated with better PFS (P < 0.001). Similarly, among patients with the same histopathology, negative PET/CT was also associated with a significantly longer PFS (P < 0.001). FDG PET/CT demonstrated a good diagnostic performance in patients with recurrent TETs and had an important prognostic value in assessing the risk of disease progression.

The International Thymic Malignancy Interest Group Classification of Thymoma Recurrence: Survival Analysis and Perspectives

INTRODUCTION

The International Thymic Malignancy Interest Group (ITMIG) classifies thymoma recurrences on the basis of the topographic location, but its effectiveness in prognosis prediction has not been well investigated yet. Aims of this study are to analyze survival outcome of patients surgically treated for thymoma recurrence according to the ITMIG recurrence classification and to investigate possible alternatives.

METHODS

From January 1, 1990, to January 7, 2017, data on 135 surgically treated patients for thymoma recurrence from three high-volume centers were collected and retrospectively analyzed. Patients were classified according to the ITMIG classification as local, regional, and distant. The ITMIG classification and alternative classifications were correlated to overall survival (OS).

RESULTS

According to the ITMIG classification, recurrence was local in 17 (12.5%), regional in 97 (71.8%), and distant in 21 (15.7%) patients, with single localization in 38 (28.2%) and multiple localizations in 97 (71.8%). The 5- and 10-year OS were 79.9% and 49.7% in local, 68.3% and 52.6% in regional, and 66.3% and 35.4% in distant recurrences, respectively, but differences were not statistically significant (p = 0.625). A significant difference in survival was present considering single versus multiple localizations: 5- and 10-year OS of 86.2% and 81.2% versus 61.3% and 31.5% (p = 0.005, hazard ratio = 7.22, 95% confidence interval: 0.147-0.740), respectively. Combining the localization number with the recurrence site, ITMIG locoregional single recurrence had a statistically significant better survival compared with patients with ITMIG locoregional multiple recurrence or ITMIG distant recurrence (p = 0.028). Similarly, a significant difference was present considering intrathoracic single versus intrathoracic multiple versus distant recurrence (p = 0.024).

CONCLUSIONS

The ITMIG classification for thymoma recurrence did not have significant survival differences comparing local, regional, and distant recurrences. Integrating this classification with the number of the localizations may improve its effectiveness in prognosis prediction.

Educational Case: Thymoma

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, seehttp://journals.sagepub.com/doi/10.1177/2374289517715040. ¹

Vascular Involvement in Thymic Epithelial Tumors: Surgical and Oncological Outcomes

BACKGROUND

The involvement of mediastinal great vessels is common in advanced stage thymic tumors, which makes their surgical resection challenging. Moreover, the impact of vascular involvement on the oncological prognosis is still unclear. The aim of this study is to investigate the surgical and oncological outcomes and the impact of vascular involvement in a population of patients operated for advanced stage thymic tumors.

METHODS

A retrospective analysis on four hundred and sixty-five patients undergoing resection for advanced stage (Masaoka III-IV) thymic tumors in a single high-volume center was performed. One hundred forty-four patients met the inclusion criteria and were eligible for the study. Patients were divided in two groups according to the presence or absence of vascular involvement.

RESULTS

the two groups did not differ for the baseline characteristics and showed comparable surgical outcomes. Vascular involvement was not associated with worse overall survival but with an increased recurrence rate (p = 0.03). Multivariable analysis demonstrated a higher risk of recurrence in patients without R0 resection (HR 0.11, 0.02-0.54, p = 0.006) and with thymic carcinoma (HR 2.27, 1.22-4.24, p = 0.01).

CONCLUSIONS

resection of thymic tumors with vascular involvement can be performed with optimal surgical results in a high volume center. From the oncological point of view, the involvement of the great vessels seems to be associated with a higher recurrence rate without affecting long-term survival.

Correlation of Computed Tomography Parameters with Histology, Stage and Prognosis in Surgically Treated Thymomas

Background and objectives: The histological classification and staging of thymic tumors remains a matter of debate. The correlation of computed tomography (CT) parameters with tumor histology and stage also still has to be completely assessed. The aim of this study was therefore to analyze the correlation of radiological parameters with histological and staging classifications of thymomas evaluating their prognostic role. Methods: Data of 50 patients with thymoma submitted to a complete surgical treatment between 2005 and 2015 were retrospectively analyzed. Tumors were classified according to the WHO and Suster and Moran (S&M) histological classifications and to the Masaoka-Koga and tumor, node and metastases (TNM) staging systems. The correlation of CT features with histology and stage and the prognostic role of histopathological and radiological features were assessed. Results: Five-year overall (OS) and disease-free survival (DFS) were 90.3% and 81.1%, respectively. A significant correlation of DFS with the Masaoka-Koga (p = 0.001) and TNM staging systems (p = 0.002) and with the S&M (p = 0.02) and WHO histological classifications (p = 0.04) was observed. CT scan features correlated with tumor stage, histology and prognosis. Moderately differentiated tumors (WHO B3) had a significantly higher incidence of irregular shape and contours (p = 0.002 and p = 0.001, respectively) and pericardial contact (p = 0.036). A larger tumor volume (p = 0.03) and a greater length of pleural contact (p = 0.04) adversely influenced DFS. The presence of pleural (p < 0.001) or lung invasion (p = 0.02) and of pleural effusion (p = 0.004) was associated with a significantly worse OS. Conclusions: Pre-operative CT scan parameters correlate with stage and histology, and have a prognostic role in surgically treated thymomas.

Thymoma-associated myasthenia gravis: Clinical features and predictive value of antiacetylcholine receptor antibodies in the risk of recurrence of thymoma

Background

Thymoma‐associated myasthenia gravis (TAMG) is one of the subtypes of myasthenia gravis with autoantibodies against the acetylcholine receptor (AChR‐Ab). We analyzed the clinical features of our cohort of TAMG patients and the changes in AChR‐Ab titer before and after thymectomy in order to identify factors predicting thymoma relapses.

Methods

We retrospectively assessed: age of MG onset, MG clinical status according to MGFA (Myasthenia Gravis Foundation of America), epoch of thymectomy, post‐thymectomy status, oncological features and surgical approach. AChR‐Ab dosages were measured both before and after thymectomy. Linear regression models were applied to identify clinical determinants of AChR‐Ab titers and the Cox regression model was fitted to estimate the factors associated with the risk of thymoma recurrence.

Results

The study sample included 239 MG patients, 27 of whom experienced one or more recurrences (median follow‐up time: 4.8 years). The AChR‐Ab titers decreased after first thymectomy (P < 0.001); the decrease was more pronounced in female patients (P = 0.05), in patients diagnosed with MG at an older age (P = 0.003), and in those who had lower MG stage before surgery (P = 0.02) or higher Masaoka‐Koga stage (P = 0.005). The risk of relapse was closely linked with the age of the patient, the Masaoka‐Koga stage and the surgical approach.

Conclusions

Presurgery levels of AChR‐Ab or their change after surgery were not associated with thymoma recurrence. The reduction of AChR‐Ab titers after thymectomy confirms an immunological role of thymoma in the pathogenesis of MG.

Key points

Significant findings of the study: Young MG patients with an advanced Masaoka staging score of the primary tumor who underwent thymectomy with approaches different from sternotomy and VATS should be monitored for high risk of recurrence.

What this study adds: No other study has ever investigated the changes in AChR‐Ab titers before and after thymectomy in a large cohort of TAMG patients. The reduction of AChR‐Ab titers after thymectomy suggests an immunological role of thymoma in the pathogenesis of MG.

Surgical management of thymic epithelial tumors

Resection is the mainstay of treatment for thymic epithelial tumors (TETs), with complete removal of the tumor and involved organs being the ultimate aim. The choice of surgical approach plays a major role in defining treatment success, and the optimal choice of method should thus provide an adequate surgical view to achieve complete tumor resection. While median sternotomy is considered the gold standard for access to the mediastinum, several minimally invasive approaches to thymectomy have been described, including video-assisted robotic-assisted thymectomy, although the oncological outcomes of that procedure remain unclear. A multimodal approach incorporating chemotherapy or chemoradiotherapy followed by extended surgery may improve resectability and outcomes for patients with advanced TETs. Surgical debulking is also reportedly acceptable for invasive thymoma because of its potential for achieving favorable outcomes. Re-resection is an acceptable option for patients with recurrent thymoma after initial resection, and repeat resection for recurrent pleural dissemination seems effective. Here, the literature on current clinical practices in the surgical management and treatment of TETs is reviewed.

Treatment Outcome and Prognostic Factors of Malignant Thymoma - A Single Institution Experience

Objective:

Our objectives are to investigate the clinicopathological features, treatment modalities, and prognostic and prognostic factors in order to estimate long-term outcomes for patients with thymoma and thymic carcinoma at our institution.

Methods:

We reviewed all patients diagnosed with thymic malignancies malignancies over a period of 38 years (from 1976 to 2014). Patients were identified using a single institution database at King Faisal Specialist Hospital and Research Center (KFSH and RC), Riyadh. Demographic data, clinical staging, histopathology classification, treatment approaches, and survival data were collected. Data Analysis was performed using both the Kaplan–Meier method and Cox proportional hazards modeling.

Results:

The fifty-six identified patients consists of 30 females (53.6%) and 26 males (46.4%). The median age at diagnosis was 39 years. About 37% of the patients were diagnosed with myasthenia gravis (MG). There was a significant association between the WHO histologic classification and the Masaoka stage (p= 0.018). The estimated 5-year overall survival rate was 88.6% for patients with thymic malignancies. The median survival time of thymoma and thymic carcinoma was 61 and 14 months, respectively. The univariate analysis suggested that histology (thymoma versus thymic carcinoma, p= 0.044) and Masaoka stage (II-III versus IV, p= 0.048) were independent prognostic factors affecting overall survival. Histology (p = 0.044) was found to be an independent predictor of overall survival.

Conclusion:

The findings of this study indicates that late Masaoka-Koga staging and histology types are significantly associated with extended overall survival. Similarly, surgical resection and multimodality treatments play a significant role in thymic malignancies neoplasms therapy strategies to prolong survival rates.

Relationship Between Computed Tomography Imaging Features and Clinical Characteristics, Masaoka-Koga Stages, and World Health Organization Histological Classifications of Thymoma

Objectives: Computed tomography (CT) is an important technique for evaluating the condition and prognosis of patients with thymomas, and it provides guidance regarding treatment strategies. However, the correlation between CT imaging features, described using standard report terms, and clinical characteristics, Masaoka–Koga stages, and World Health Organization (WHO) classifications of patients with thymomas has not been described in detail nor has risk factor analysis been conducted.

Methods: Overall, 159 patients with thymomas who underwent preoperative contrast-enhanced CT between September 2011 and December 2018 were retrospectively reviewed. We assessed the clinical information, CT imaging features, and pathological findings for each patient. A total of 89 patients were specially used to evaluate postoperative recurrence or metastasis between September 2011 and December 2015 to obtain an appropriate observation period. The relationship between CT imaging features and clinical characteristics, Masaoka–Koga stage, and WHO histological classification were analyzed, and related risk factors based on CT imaging features were identified.

Results: CT imaging features did not significantly differ based on sex or age. Some imaging features demonstrated significant differences between the groups with and without related clinical characteristics. Contour (odds ratio [OR] = 3.711, P = 0.005), abutment ≥50% (OR = 4.277, P = 0.02), and adjacent lung abnormalities (OR = 3.916 P = 0.031) were independent risk factors for relapse or metastasis. Among all imaging features, there were significant differences between stage I/II and III/IV lesions in tumor size, calcification, infiltration of surrounding fat, vascular invasion, pleural nodules, elevated hemidiaphragm, and pulmonary nodules. Tumor size (odds ratio = 1.261, P = 0.014), vascular invasion (OR = 2.526, P = 0.023), pleural nodules (OR = 2.22, P = 0.048), and pulmonary nodules (OR = 3.106, P = 0.006) were identified as independent risk factors. Tumor size, contour, internal density, infiltration of surrounding fat, and pleural effusion significantly differed between low- and high-risk thymomas. Tumor size (OR = 1.183, P = 0.048), contour (OR = 2.288, P = 0.003), internal density (OR = 2.192, P = 0.024), and infiltration of surrounding fat (OR = 2.811 P = 0.005) were independent risk factors.

Conclusions: Some CT imaging features demonstrated significant correlations with clinical characteristics, Masaoka–Koga clinical stages, and WHO histological classifications in patients with thymomas. Familiarity with CT features identified as independent risk factors for these related clinical characteristics can facilitate preoperative evaluation and treatment management for the patients with thymoma.

Third distant recurrence of benign thymoma in a patient with myasthenia gravis

Myasthenia gravis (MG) is an autoimmune disease where antibodies attack the presynaptic terminals at the neuromuscular junction causing progressive weakness. Associated with thymomas, resection can improve symptoms. A 29-year-old woman with MG who underwent two previous thymectomies, at ages 11 and 15 presented 14 years later with recurrent MG symptoms and an anterior mediastinal mass. Robotic-assisted thoracoscopic excision of the mediastinal mass was performed without complications. She recovered well and had improvement of her MG symptoms. Thymectomy can significantly improve symptoms in MG even for patients who do not have a thymoma. Reports of distant benign thymoma recurrence are rare. MG patients require continued monitoring and vigilance, even after thymectomy. Benign thymomas can recur even after significant time intervals, and utilisation of the robotic platform for recurrent thymoma excision is safe, even following two sternotomies. Patient symptoms improve with redo thymectomy.

Thymoma Recurrence and its Predisposing Factors in Iranian Population: a Single Center Study

BACKGROUND

Thymoma is relatively rare tumor. Prognosis and patients' outcome vary across different studies. We aimed to study the predisposing factors causing tumor recurrence in thymoma patients.

MATERIALS AND METHODS

A total of 43 thymoma or thymic carcinoma patients treated at the National Institute of Tuberculosis and Lung Disease (NRITLD), Masih Daneshvari Hospital from September 2005 to January 2017 were evaluated. The primary endpoint was the progression free survival (PFS). The relation of predisposing factors to PFS was studied.

RESULTS

Median age was 55 years old. The mean of follow-up duration was 22.9 months. The most prevalent pathology was thymoma unspecified. Pure red cell aplasia (n=3, 6.9%) was the most prevalent Para neoplastic syndrome. Most of the patients (n=23, 54%) were in stage III and IV Masaoka-Koga staging system. Disease progression was observed in 17 patients (39. 5%). Most recurrences occurred locally. None of demographic characteristics differed between patients who experienced disease recurrence and those who did not. After univariate and multivariate analysis, predisposing factor for disease progression was only Masaoka-Koga stage (P-value=0.015 and 0.031 respectively).

CONCLUSION

In this study, among different probable predisposing factors, only Masaoka-Koga stage had significant effect on disease recurrence. Large case-control studies may be required for better evaluation of risk factors.

Acquired neuromyotonia in thymoma-associated myasthenia gravis: a clinical and serological study

Background and purpose

Acquired neuromyotonia can occur in patients with thymoma, alone or in association with myasthenia gravis (MG), but the clinical prognostic significance of such comorbidity is largely unknown. The clinico‐pathological features were investigated along with the occurrence of neuromyotonia as predictors of tumour recurrence in patients with thymoma‐associated myasthenia.

Methods

A total number of 268 patients with thymomatous MG were studied retrospectively. Patients with symptoms of spontaneous muscle overactivity were selected for autoantibody testing using immunohistology for neuronal cell‐surface proteins and cell‐based assays for contactin‐associated protein 2 (CASPR2), leucine‐rich glioma inactivated 1 (LGI1), glycine receptor and Netrin‐1 receptor antibodies. Neuromyotonia was diagnosed according to the presence of typical electromyography abnormalities and/or autoantibodies against LGI1/CASPR2.

Results

Overall, 33/268 (12%) MG patients had a thymoma recurrence. Five/268 (2%) had neuromyotonia, four with typical autoantibodies, including LGI1 (n = 1), CASPR2 (n = 1) or both (n = 2). Three patients had Netrin‐1 receptor antibodies, two with neuromyotonia and concomitant CASPR2+LGI1 antibodies and one with spontaneous muscle overactivity without electromyography evidence of neuromyotonia. Thymoma recurrence was more frequent in those with (4/5, 80%) than in those without (28/263, 10%, P < 0.001) neuromyotonia. Neuromyotonia preceded the recurrence in 4/5 patients. In univariate analysis, predictors of thymoma recurrence were age at thymectomy [odds ratio (OR) 0.95, 95% confidence interval (CI) 0.93–0.97], Masaoka stage ≥IIb (OR 10.73, 95% CI 2.38–48.36) and neuromyotonia (OR 41.78, 95% CI 4.71–370.58).

Conclusions

De novo occurrence of neuromyotonia in MG patients with previous thymomas is a rare event and may herald tumour recurrence. Neuronal autoantibodies can be helpful to assess the diagnosis. These observations provide pragmatic risk stratification for tumour vigilance in patients with thymomatous MG.

A novel prognostic signature of seven genes for the prediction in patients with thymoma

Purpose

A thymoma is a tumor arising from the epithelium of the thymus, mostly occurring in the anterior mediastinum. The incidence of this disease is low and research progress in this field is slow. Consequently, there is an urgent need to investigate the correlation between molecular regulation and the prediction of survival and prognosis in patients with thymoma.

Methods

We collected thymoma datasets from The Cancer Genome Atlas (TCGA). Differentially expressed genes (DEGs) of TCGA datasets were then determined using R software. A gene signature was obtained by screening prognostic DEGs from the TCGA datasets using univariate and multivariate Cox survival analysis. The summation of the weighted expression levels was calculated as a risk score, which could then be used to predict the survival rate and prognosis of patients with thymoma. The validity of this model was verified by the analysis of receiver operating characteristic (ROC) curves and area under the curve (AUC).

Results

In total, 297 DEGs were identified from the integrated results of TCGA datasets. A seven-gene signature, along with a regression model of prognostic risk, was obtained by Cox survival analysis. The expression levels of the seven genes were then weighted and summed to calculate the risk score for each sample. Patients were effectively divided into high- and low-risk groups using the median risk score (P < 0.05). ROC analysis showed that this Cox regression model was effective in predicting the prognosis of patients with thymus tumors (AUC = 0.983, P < 0.05).

Conclusion

For the first time, we identified an effective seven-gene signature in patients with thymic tumors. In the future, the risk and prognosis of patients can be preliminarily assessed using this model, although further testing is required to improve rigor.

Treatment and prognostic factors of patients with thymic epithelial tumors at first recurrence or progression

AIM

The treatment of patients with recurrent or progressive thymic epithelial tumors remains uncertain due to limited data in this rare disease.

MATERIALS & METHODS

A retrospective 10-year monoinstitutional analysis was conducted on 25 patients with first recurrence or disease progression following primary treatment.

RESULTS

Twenty patients had thymoma, five thymic carcinomas. Ten patients (40%) received surgery, four (40%) following chemotherapy; 17 (68%) had chemotherapy, with a combination regimen in 16 of them (94%). Surgery had a significant effect both on overall survival and progression-free survival-2 by univariate analysis (p = 0.04), combination chemotherapy only on progression-free survival-2 (p = 0.03).

CONCLUSION

Combination chemotherapy and surgery at first recurrence/progression of thymic epithelial tumors were associated with improved survival.

DISCUSSION

Although several limitations may have affected this retrospective study on a relatively small number of patients with this rare entity of recurrent thymic malignancies, we suggest the use of combination chemotherapy and surgery at their first recurrence may have contributed to the high overall and progression-free survival observed with adequate follow-up and deserve further investigations in broader retrospective and comparative studies.

Identification of prognostic and subtype-specific potential miRNAs in thymoma

AIM

We performed a study to identify the role of microRNA in thymoma.

PATIENTS & METHODS

One hundred twenty-three thymoma patients with clinical information and miRNA expression data from The Cancer Genome Atlas were included in the study. Comprehensive bioinformatics analysis was integrated in our analysis.

RESULTS & CONCLUSION

Seven miRNAs were found to be associated with overall survival (p < 0.001). Another four miRNAs were found to be associated with disease-free survival (p < 0.001). Type C thymoma can be distinguished from nontype C thymoma by miRNAs. Interestingly, seven miRNAs showed both prognostic and subtype-specific potential. Our findings suggest that miRNAs can be used for prognostic prediction and subtype stratification.