Management of Thymic Tumors: A Survey of Current Practice among Members of the European Society of Thoracic Surgeons

Multiparametric Evaluation of Radiomics Features and Dual-Energy CT Iodine Maps for Discrimination and Outcome Prediction of Thymic Masses

RATIONALE AND OBJECTIVES

To investigate the diagnostic value of radiomics features and dual-source dual-energy CT (DECT) based material decomposition in differentiating low-risk thymomas, high-risk thymomas, and thymic carcinomas.

MATERIALS AND METHODS

This retrospective study included 32 patients (16 males, mean age 66 ± 14 years) with pathologically confirmed thymic masses who underwent contrast-enhanced DECT between 10/2014 and 01/2023. Two experienced readers evaluated all patients regarding conventional radiomics features, as well as DECT-based features, including attenuation (HU), iodine density (mg/mL), and fat fraction (%). Data comparisons were performed using analysis of variance and chi-square statistic tests. Receiver operating characteristic curve analysis and Cox-regression tests were used to discriminate between low-risk/high-risk thymomas and thymic carcinomas.

RESULTS

Of the 32 thymic tumors, 12 (38%) were low-risk thymomas, 11 (34%) were high-risk thymomas, and 9 (28%) were thymic carcinomas. Values differed significantly between low-risk thymoma, high-risk thymoma, and thymic carcinoma regarding DECT-based features (p ≤ 0.023) and 30 radiomics features (p ≤ 0.037). The area under the curve to differentiate between low-risk/high-risk thymomas and thymic cancer was 0.998 (95% CI, 0.915-1.000; p < 0.001) for the combination of DECT imaging parameters and radiomics features, yielding a sensitivity of 100% and specificity of 96%. During a follow-up of 60 months (IQR, 35-60 months), the multiparametric approach including radiomics features, DECT parameters, and clinical parameters showed an excellent prognostic power to predict all-cause mortality (c-index = 0.978 [95% CI, 0.958-0.998], p = 0.003).

CONCLUSION

A multiparametric approach including conventional radiomics features and DECT-based features facilitates accurate, non-invasive discrimination between low-risk/high-risk thymomas and thymic carcinomas.

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.

Thymic Epithelial Tumors: An Evolving Field

Despite their rarity, thymic epithelial tumors (TETs) have attracted much interest over the years, leading to an impressive number of histological and staging classifications. At present, TETs are divided by the WHO classification into four main subtypes: type A, type AB, and type B thymomas (subdivided into B1, B2, and B3), and thymic carcinomas, going from the more indolent to the most aggressive ones. Among many debated staging proposals, the TNM and the Masaoka-Koga staging systems have been widely accepted and used in routine practice. The four-tiered histological classification is symmetrically mirrored by the molecular subgrouping of TETs, which identifies an A-like and an AB-like cluster, with frequent GTF2I and HRAS mutations; an intermediate B-like cluster, with a T-cell signaling profile; and a carcinoma-like cluster comprising thymic carcinomas with frequent CDKN2A and TP53 alterations and a high tumor molecular burden. Molecular investigations have opened the way to tailored therapies, such as tyrosine kinase inhibitors targeting KIT, mTOR, and VEGFR, and immune-checkpoints that have been adopted as second-line systemic treatments. In this review, we discuss the crucial events that led to the current understanding of TETs, while disclosing the next steps in this intriguing field.

Mediastinal tumours and pseudo-tumours: a comprehensive review with emphasis on multidisciplinary approach

The diagnosis of a mediastinal mass may be challenging for clinicians, since lesions arising within the mediastinum include a variety of disease entities, frequently requiring a multidisciplinary approach. Age and sex represent important information, which need to be integrated with imaging and laboratory findings. In addition, the location of the mediastinal lesion is fundamental; indeed, we propose to illustrate mediastinal diseases based on the compartment of origin. We consider that this structured approach may serve as hint to the diagnostic modalities and management of mediastinal diseases. In this review, we present primary mediastinal tumours in the evolving context of new diagnostic and therapeutic tools, with recently described entities, based on our own experience with >900 cases encountered in the past 10 years.

Given the mediastinal anatomical heterogeneity, the correct positioning of mediastinal lesions becomes primal, in order to first establish a clinical suspicion and then to assist in planning biopsy and surgical procedurehttps://bit.ly/3p0gsk3

Role of quantitative energy spectrum CT parameters in differentiating thymic epithelial tumours and thymic cysts

AIM

To explore the utility of multiple energy spectrum computed tomography (CT) parameters in distinguishing thymic epithelial tumours (TETs) from thymic cysts among lesions <5 cm in diameter.

MATERIALS AND METHODS

Data pertaining to 56 patients with TETs and thymic cysts <5 cm in diameter were assessed retrospectively. All patients underwent surgical resection and the diagnosis was confirmed histopathologically. Thirty-five patients with TETs (average age, 51.97 years) and 21 patients with thymic cysts (average age, 50.54 years) were included. The region of interest for the lesion on the energy spectrum CT was delineated on the post-processing workstation, and multiple parameters of the energy spectrum CT were obtained. The diagnostic efficacies of the parameters were analysed using receiver operating characteristic (ROC) curves.

RESULTS

To distinguish small TETs from thymic cysts, a single-energy CT value of 60 keV showed good differential diagnostic performance in the arterial phase (cut-off value = 68.42 HU; area under the curve [AUC] = 0.978), a single-energy CT value of 70 keV showed good differential diagnostic performance in the venous phase (cut-off value = 59.77 HU; AUC = 0.956). In the arterial and venous phases, effective atomic numbers of 8.065 and 8.175, respectively, were used as cut-off values to distinguish small TETs from thymic cysts (AUC = 0.972 and AUC = 0.961, respectively). Iodine concentrations of 10.99 and 11.05 were used as cut-off values to distinguish small TETs from thymic cysts (AUC = 0.956 and AUC = 0.924, respectively).

CONCLUSION

According to the present study, energy spectrum CT parameters may have clinical value in the differential diagnosis of TETs and thymic cysts.

Quantitative Histogram Analysis of T2-Weighted and Diffusion-Weighted Magnetic Resonance Images for Prediction of Malignant Thymic Epithelial Tumors

PURPOSE

To assess the value of histogram analysis for differentiating a high-risk thymic epithelial tumor (TET) from a low-risk TET using T2-weighted images and the apparent diffusion coefficient (ADC).

METHODS

Forty-nine patients with histopathologically proven TET after thymectomy were enrolled in this study and retrospectively classified as having low-risk TET (low-risk thymoma) or high-risk TET (high-risk thymoma or thymic carcinoma). Twelve parameters were obtained from the quantitative histogram analysis. The histogram parameters were compared using the Mann-Whitney U test. Diagnostic efficacy was estimated by receiver-operating characteristic curve analysis.

RESULTS

Twenty-five patients were classified as having low-risk TET and 24 as having high-risk TET. The mean ADC value showed diagnostic efficacy for differentiating high-risk TET from low-risk TET, with an area under the curve of 0.7, and was better than when using conventional methods alone.

CONCLUSION

The ADC-based histogram analysis could help to differentiate between high-risk and low-risk TETs.

Prognostic factors for survival in advanced thymomas: The role of the number of involved structures

BACKGROUND AND OBJECTIVES

The Masoka-Koga and tumor node metastases staging systems for thymoma are based on structures involved, but the prognostic role of the number of infiltrated/involved structures is still debated. We analyzed the prognostic role of involved structures and their combinations in locally advanced thymomas patients.

METHODS

Data on 174 surgically treated locally advanced thymoma patients from 1/01/1990 to 31/12/2015 were reviewed. Clinical and pathological characteristic, involved structures, number of involved structures and different combinations were correlated to cancer specific survival (CSS) using Kaplan-Meier product-limit method.

RESULTS

Five and 10-year CSS was 92% and 87%. Masaoka Stage 3 (p < 0.001), absence of pericardial involvement (p = 0.001), number of involved structures (p = 0.018), R0 (p < 0.001) and adjuvant radiotherapy (p = 0.008) were favorable prognostic CSS factors. A significant better prognosis was present in ≤2 involved structures vs >2 involved structures (5- and 10-year CSS: 95% and 93% vs. 80% and 51%). Multivariable analysis confirmed as independent prognostic factor R0 (p = 0.033, hazard ratio [HR]: 0.093, 95% confidence interval [CI] 0.010-0.827) and number of involved structures (p = 0.046, HR: 0.187, 95% CI: 0.036-0.968). In Masaoka Stage 3, patients with ≤2 involved structures had a significant better CSS than patients with >2 (10-year CSS: 98% vs. 73%, p = 0.008).

CONCLUSIONS

The number of involved structures and the concomitant involvement of the pericardium seems to be associated with a poor prognosis in surgically treated advanced thymoma patients.

Invasive thymoma - Which patients benefit from post-operative radiotherapy?

BACKGROUND

The aim of this study is to identify patients with thymoma who should receive post-operative radiotherapy.

METHODS

The Surveillance, Epidemiology, and End Results database was queried for stage IIB-IV thymoma patients diagnosed during 1988-2015. We analyzed the prognostic implications of various clinical-pathological factors by comparing the outcomes of those who received surgery with and without post-operative radiotherapy.

RESULTS

A total of 1120 patients were identified; 62% received post-operative radiotherapy and 38% underwent surgery alone. In a propensity-matched cohort of 812 patients, no survival difference was seen in World Health Organization A, AB, B1, B2, or B3 tumors with the addition of post-operative radiotherapy to surgery (p>0.05). Post-operative radiotherapy also did not improve survival over surgery alone for tumors ≥ or < less than the 4 cm, 7 cm, 10 cm, and 13 cm cutoffs, all p>0.05. Post-operative radiotherapy was an independent, positive prognostic indicator only in the subgroup with stage III disease and in those receiving chemotherapy in addition to post-operative radiotherapy, both p<0.05.

CONCLUSIONS

Patients with stage III thymoma are most likely to benefit from the addition of post-operative radiotherapy to surgical treatments. Tumor size or World Health Organization histology alone should not be criteria for determining the need for post-operative radiotherapy in locally advanced thymoma. Masaoka-Koga stage, which has traditionally been used to help make such decisions, appears to be the most reliable determinant of the use of post-operative radiotherapy.

Radiotherapy for thymic epithelial tumours: a review

Thymic epithelial tumours (TETs) represent a rare disease, yet they are the most common tumours of the anterior mediastinum. Due to the rare occurrence of TETs, evidence on optimal treatment is limited. Surgery is the treatment of choice in the management of TETs, while the role of postoperative radiotherapy (PORT) remains unresolved. PORT remains debated for thymomas, especially in completely resected stage II tumours, for which PORT may be more likely to benefit in the presence of aggressive histology (WHO subtype B2, B3) or extensive transcapsular invasion (Masaoka-Koga stage IIB). For stage III thymoma, evidence suggests an overall survival (OS) benefit for PORT after complete resection. For incompletely resected thymomas stage II or higher PORT is recommended. Thymic carcinomas at any stage with positive resection margins should be offered PORT. Radiotherapy plays an important role in the management of unresectable locally advanced TETs. Induction therapy (chemotherapy or chemoradiation) followed by surgery may be useful for locally advanced thymic malignancies initially considered as unresectable. Chemotherapy only is offered in patients with unresectable, metastatic tumours in palliative intent, checkpoint inhibitors may be promising for refractory diseases. Due to the lack of high-level evidence and the importance of a multidisciplinary approach, TETs should be discussed within a multidisciplinary team and the final recommendation should reflect individual patient preferences.

Thymic Epithelial Neoplasms: Tumor-Node-Metastasis Staging

Thymic epithelial neoplasms are a group of malignant tumors that includes thymoma, thymic carcinoma, and thymic neuroendocrine tumors. Although several staging systems have been developed over the years for use with these cancers, they have been interpreted and implemented in a nonuniform manner. Recently, the International Association for the study of Lung Cancer and the International Thymic Malignancy Interest Group developed a tumor-node-metastasis staging system that has been universally accepted and correlates with patient survival and outcomes. Although pathologic staging is determined by histologic examination of the resected tumor, imaging plays an important role in clinical staging and is important for informing therapeutic decisions.

Classification and staging of thymoma

The appropriate therapy and prognosis of patients with thymic malignancies is decisively influenced by the local extent and dissemination of the tumor. For this reason, a staging system that reflects these factors is essential. Mainly the Masaoka-Koga classification, which was introduced in 1994, has been applied for this purpose. The rarity of thymic malignancies makes it difficult not only to establish internationally standardized diagnostics and treatment, but also to progress staging. Besides, efforts were made to adapt the classification into a tumor-node-metastasis-based (TNM) system for standardization with the staging of other tumor entities. The 2017 published 8th edition of the TNM Classification of Malignant Tumors introduced several adjustments based on a proposal of the International Association for the Study of Lung Cancer (IASLC) and the International Thymic Malignancy Interest Group (ITMIG). Compared to the Masaoka-Koga classification, surgically good resectable tumor involvements like pericardium, mediastinal fat or mediastinal pleura have been shifted to lower stages. Thus, even more than in Masaoka-Koga classification, tumors are basically divided into completely resectable and thus surgically treatable tumors (stage I, II, IIIA) and advanced stages (stage IIIB, IVA and IVB) that require multimodal therapy.

LINC00174 is a novel prognostic factor in thymic epithelial tumors involved in cell migration and lipid metabolism

Long non-coding RNAs are emerging as new molecular players involved in many biological processes, such as proliferation, apoptosis, cell cycle, migration, and differentiation. Their aberrant expression has been reported in variety of diseases. The aim of this study is the identification and functional characterization of clinically relevant lncRNAs responsible for the inhibition of miR-145-5p, a key tumor suppressor in thymic epithelial tumors (TETs). Starting from gene expression analysis by microarray in a cohort of fresh frozen thymic tumors and normal tissues, we identified LINC00174 as upregulated in TET. Interestingly, LINC00174 expression is positively correlated with a 5-genes signature in TETs. Survival analyses, performed on the TCGA dataset, showed that LINC00174 and its associated 5-genes signature are prognostic in TETs. Specifically, we show that LINC00174 favors the expression of SYBU, FEM1B, and SCD5 genes by sponging miR-145-5p, a well-known tumor suppressor microRNA downregulated in a variety of tumors, included TETs. Functionally, LINC00174 impacts on cell migration and lipid metabolism. Specifically, SCD5, one of the LINC00174-associated genes, is implicated in the control of lipid metabolism and promotes thymic cancer cells migration. Our study highlights that LINC00174 and its associated gene signature are relevant prognostic indicators in TETs. Of note, we here show that a key controller of lipid metabolism, SCD5, augments the migration ability of TET cells, creating a link between lipids and motility, and highlighting these pathways as relevant targets for the development of novel therapeutic approaches for TET.

Report from the European Society of Thoracic Surgeons prospective thymic database 2017: a powerful resource for a collaborative global effort to manage thymic tumours

OBJECTIVES

We queried the European Society of Thoracic Surgeons (ESTS) prospective thymic database for descriptive analysis and for comparison with the ESTS retrospective thymic database (1990-2010).

METHODS

Data were retrieved (January 2007-November 2017) for 1122 patients from 75 ESTS institutions.

RESULTS

There were 484 (65%) thymomas, 207 (28%) thymic carcinomas and 49 (7%) neuroendocrine thymic tumours. Staging (Masaoka) included 483 (67%) stage I and II, 100 (14%) stage III and 70 (10%) stage IV tumours. The new International Association for the Study of Lung Cancer/International Thymic Malignancies Interest Group tumour, node and metastasis (TNM) classification was available for 224 patients and including 177 (85%) stage I-II, 37 (16%) stage IIIA and 10 (4%) stage IIIB tumours. Chemotherapy as induction and adjuvant treatment was used in 14% and 15% of the patients. Radiotherapy was almost exclusively used postoperatively (24%). A minimally invasive surgical approach (video-assisted thoracic surgery/robotic-assisted thoracic surgery) was used in 276 (33%) patients. The overall recurrence rate was 10.8% (N = 38). Compared to the ESTS retrospective database, the increased prevalence of thymic carcinomas (from 9% to 28%) and neuroendocrine thymic tumours (from 2% to 7%), an increase in the use of minimally invasive techniques (from 6% to 34%) and a wider use of chemotherapy as induction (from 9% to 15%) and adjuvant (from 2% to 16%) treatment were observed in the prospective database. The introduction of a set of variables considered essential for the data use ('minimum dataset') resulted in an increased average completeness rate.

CONCLUSIONS

The reported data from the ESTS prospective thymic database confirm the recent trends in the management of thymic tumours. The ESTS prospective thymic database represents a powerful resource open to all ESTS members for the global effort to manage these rare tumours.

[Extended Resection of Locally Advanced Thymic Tumours in Stage III]

In the treatment of locally advanced thymic tumours, specific diagnostic testing is required, with a multimodal therapeutic approach consisting of surgery, radio- and/or chemotherapy. The complete resection of the tumour represents the most important prognostic factor with regard to recurrence-free and long-term survival. Local invasive growth of malignant thymic tumours into neighbouring mediastinal structures is classified as Masaoka-Koga stage III. Surgical resection can be performed primarily or after induction therapy, depending on the extent of the tumour. However, in some cases these tumours must be classified as non-resectable, so that only palliative radio-/chemotherapy remains as therapeutic option. TNM classification for malignant thymic tumours has been recently introduced. This resembles the established Masaoka-Koga classification in many aspects, but also includes some therapy-relevant changes. A differentiation is made between stages IIIA and IIIB, with the aim of assessing the resectability of advanced thymic tumours in a more differentiated manner and consequent planning of the therapy concept. Besides the thymus, thymoma, perithymic tissue, mediastinal pleura (stage I) or pericardium (stage II), all infiltrated structures should be removed "en bloc", if possible in stage III tumours. While the lung, brachiocephalic vessels or extrapericardial pulmonary vessels can still be resected and reconstructed if necessary, infiltration of the aorta or intrapericardial pulmonary vessels often limits macroscopically complete resection.

Thymic Epithelial Tumors as a Model of Networking: Development of a Synergistic Strategy for Clinical and Translational Research Purposes

Among the group of thymic epithelial tumors (TET), thymomas often show either uncertain or explicit malignant biological behavior, local invasiveness, and intrathoracic relapse and are often difficult to manage. From the initial stages, thymic carcinomas tend to show aggressive behavior and extrathoracic spread. Moreover, the interplay of epithelial cells and thymocytes in thymomas causes complex immune derangement and related systemic autoimmune diseases. Due to their rare occurrence and to the limited funding opportunities available for rare tumors, it is challenging to make advances in clinical and translational research in TET. The authors of this paper are all members of a multidisciplinary clinical and research thoracic tumor team. Strong input was given to the team by long-standing expertise in TET in the Pathology Department. In addition, thanks to the collaboration between research units at our Institute as well as to national collaborations, over the last 10 years we were able to perform several tissue-based research studies. The most recent studies focused on microRNA and on functional studies on the thymic carcinoma cell line 1889c. The recent implementation of our biobank now provides us with a new tool for networking collaborative research activities. Moreover, the participation in a worldwide community such as ITMIG (International Thymic Malignancy Interest Group) has allowed us to significantly contribute toward fundamental projects/research both in tissue-based studies (The Cancer Genome Atlas) and in clinical studies (TNM staging of TET). Our achievements derive from constant commitment and long-standing experience in diagnosis and research in TET. New perspectives opened up due to the establishment of national [the Italian Collaborative Group for ThYmic MalignanciEs (TYME)] and European reference networks such as EURACAN, for an empowered joint clinical action in adult solid rare tumors. The challenge we face still lies in the advancement of clinical and basic science in thymic epithelial malignancies.

Clinical Experience with Thymic Cystectomy: A Single-Institution Study of 117 Cases from 2013 to 2019

Background

The aim of this study was to summarize the clinical experience of thymic cysts treatment from a single center.

Material/Methods

Clinical data, imaging, pathological results, and follow-up results of thymic cyst patients who underwent surgery from January 2013 to September 2019 were retrospectively reviewed.

Results

A total of 117 patients were enrolled, including 76 asymptomatic patients and 41 symptomatic patients. The average diameter of thymic cysts, the cysts in asymptomatic patients, and those in symptomatic patients were 31.93±19.92 mm, 29.28±17.97 mm, and 36.85±22.50 mm, respectively. The number of cysts ranged from 1 to 3 cm, 3 to 6 cm, and >6 cm in 73 cases (62.4%), 32 cases (27.3%), and 12 cases (10.3%), respectively. There was no correlation between the size of thymic cysts and the presence or absence of symptoms. Only 20 cases (17.1%) were correctly diagnosed as thymic cysts before surgery. There were 67 patients (57.3%) who underwent video-assisted thoracic surgery (VATS) and 50 cases (42.7%) underwent open surgery. Cystectomy was performed in 93 cases (79.5%) and 24 cases (20.5%) underwent simultaneous resection of thymic cysts and other thoracic tumors. Compared with the thoracotomy group, the VATS group had shorter hospital stay and chest tube indwelling time. No serious complications occurred after surgery. The median follow-up time was 45.0 months (range 4.0–84.0 months) and there was no recurrence.

Conclusions

Attention should be paid to the accuracy of preoperative diagnosis of thymic cysts and the reduction of asymptomatic thymic cystectomy. For patients who have both thymic cysts and other thoracic tumors, simultaneous surgery is safe and feasible.

Thymic epithelial tumor treatment in Japan: analysis of hospital cancer registry and insurance claims data, 2012-2014

INTRODUCTION

Thymic epithelial tumors are a rare type of neoplasm. Accordingly, it is difficult to perform phase III trials in patients with thymic epithelial tumors, and thus, no standard treatment has been established for these tumors. In this study, we aimed to investigate the current status of thymic epithelial tumor treatment in Japan.

METHODS

This retrospective observational study enrolled patients with thymic epithelial tumor whose data were recorded in a nationwide Hospital-based Cancer Registry that was linked with health insurance claims data for the registered patients between 2012 and 2014. The patients' treatment details were obtained from a health insurance claims database.

RESULTS

A total of 813 patients with thymoma and 547 with thymic carcinoma were included in the analysis. Overall, 549 (67.5%) thymoma patients underwent surgical resection alone. Among patients with thymic carcinoma, 230 (42.0%) underwent initial surgery, and 124 (53.9%) received subsequent radiotherapy and chemotherapy. Chemotherapy regimens varied across the hospitals; overall, 21 and 22 regimens were used to treat thymoma and thymic carcinoma, respectively. Platinum-based combination regimens were predominantly selected for both diseases.

CONCLUSIONS

This study revealed the real-world patterns of thymic epithelial tumor treatment in Japan. Although the nature of this study did not enable the determination of optimal treatment strategies, the simultaneous analysis of nationwide registry, insurance, efficacy and prognostic data may contribute to the establishment of a standard treatment strategy for rarely occurring cancers such as thymic epithelial tumor.

Distinguishing between Thymic Epithelial Tumors and Benign Cysts via Computed Tomography

Objective

To investigate whether computed tomography (CT) and fluorine-18-labeled fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) may be applied to distinguish thymic epithelial tumors (TETs) from benign cysts in the anterior mediastinum.

Materials and Methods

We included 262 consecutive patients with pathologically proven TETs and benign cysts 5 cm or smaller who underwent preoperative CT scans. In addition to conventional morphological and ancillary CT findings, the relationship between the lesion and the adjacent mediastinal pleura was evaluated qualitatively and quantitatively. Mean lesion attenuation was measured on CT images. The maximum standardized uptake value (SUVmax) was obtained with FDG-PET scans in 40 patients. CT predictors for TETs were identified with multivariate logistic regression analysis. For validation, we assessed the diagnostic accuracy and inter-observer agreement between four radiologists in a size-matched set of 24 cysts and 24 TETs using a receiver operating characteristic curve before and after being informed of the study findings.

Results

The multivariate analysis showed that post-contrast attenuation of 60 Hounsfield unit or higher (odds ratio [OR], 12.734; 95% confidence interval [CI], 2.506–64.705; p = 0.002) and the presence of protrusion from the mediastinal pleura (OR, 9.855; 95% CI, 1.749–55.535; p = 0.009) were the strongest CT predictors for TETs. SUVmax was significantly higher in TETs than in cysts (5.3 ± 2.4 vs. 1.1 ± 0.3; p < 0.001). After being informed of the study findings, the readers' area under the curve improved from 0.872–0.955 to 0.949–0.999 (p = 0.066–0.149). Inter-observer kappa values for protrusion were 0.630–0.941.

Conclusion

Post-contrast CT attenuation, protrusion from the mediastinal pleura, and SUVmax were useful imaging features for distinguishing TETs from cysts in the anterior mediastinum.

Metastatic or locally advanced mediastinal neuroendocrine tumours: outcome with 177Lu-DOTATATE-based peptide receptor radionuclide therapy and assessment of prognostic factors

BACKGROUND

Primary neuroendocrine tumours (NETs) of mediastinum are unusual tumours with aggressive biological behaviour with limited treatment options and guarded prognosis.

METHODS

Twenty-seven patients with histopathologically and radiologically proven metastatic or advanced mediastinal NET, who had undergone 177Lu-DOTATATE PRRT, were included in this retrospective analysis. Descriptive statistics was employed to calculate the cumulative overall survival (OS) and progression-free survival (PFS), determining correlation and strength of correlation between different variables with OS and PFS and finally, predictors of outcome (OS and PFS).

RESULTS

In all 27 patients enrolled and analyzed, complete symptomatic response was observed in 10 patients (37%), partial response in seven patients (25.9%), symptomatically stable disease in four patients (14.8%), and symptoms progressed or worsened in six patients (22.2%). Metabolic response evaluation demonstrated complete metabolic response in one patient (3.7%), partial metabolic response was seen in nine patients (33.3%), metabolically stable disease was seen in five patients (18.5%), and 12 patients (44.4%) showed metabolic disease progression. None of the patients achieved complete anatomical/morphological response, six (22.2%) showed partial response, seven (25.9%) showed stable disease, and in 14 patients (51.9%), there was morphological disease progression. At the time of analysis, 10 patients (37%) succumbed to the disease. The median PFS was 36 months and the median OS was 66 months. Bivariate analysis showed significant level of association of PFS with surgical intervention, higher cumulative PRRT dose, metabolic response, smaller sized primary lesion, and low lesional FDG uptake. With regard to OS, higher cumulative PRRT dose, low FDG uptake and longer PFS showed significant association.

CONCLUSION

Previous surgical intervention (including debulking surgery with R1 resection), higher cumulative dose of PRRT, and low FDG uptake of the tumour are associated with prolonged OS and PFS in patients with metastatic or advanced mediastinal NETs and were independent favourable prognostic markers.

Optimal management of thymic malignancies: current perspectives

Thymic epithelial tumors (TETs) belong to orphan oncology. The incidence of TETs is about 1.3–3.2 cases per million worldwide. Following pathology, evolution and prognosis are variable. The World Health Organization classification distinguishes thymomas and thymic carcinomas. TETs are composed of thymic epithelial tumoral cells and normal lymphocytes. The mean age at diagnosis is 50–60 years-old. There are no identified risk factors. TETs are frequently associated with paraneoplastic syndromes as myasthenia gravis. The complete R₀ surgical resection is the most significant prognosis factor on survival. In 2010, the French National Institute of Cancer labeled the RYTHMIC network as a specific tumor board including thoracic surgeons, oncologist, and radiation therapist to define standard of care for the management of TETs. The aim of the review was to update knowledge to optimize the standard of care.

Favourable health-related quality of life reported in survivors of thymic malignancies

OBJECTIVES

The management of patients with locally advanced thymic malignancies remains controversial. Differing combinations of surgical resection, chemotherapy and radiation are used in the management of initial and relapsed disease. Treatment-related toxicities and quality of life could inform therapeutic options. This study describes health utility scores (HUS) in survivors with locally advanced thymic malignancies and investigates the impact of multimodality regimens on HUS.

METHODS

In a cross-sectional study (2014-2017), patients with Masaoka Stage II-IVa thymic malignancies completed various self-reported questionnaires, including EuroQol-5-Dimensions with visual analogue scale (VAS), Eastern Cooperative Oncology Group (ECOG) and Edmonton Symptom Assessment Scale tools. Trimodality versus uni- or bimodality regimens and aggressive versus non-aggressive management of recurrent disease were compared using regression analyses.

RESULTS

Of the 72 patients, 43 (60%) were male with a median age of 58 years, 65 (90%) had thymoma while 7 (10%) had thymic carcinomas; and median time since diagnosis was 50.5 months (range: 3-266). Median HUS and VAS did not differ between groups (trimodality n = 24 vs uni- or bimodality n = 48: HUS = 0.77 vs 0.80, P = 0.29; VAS = 80 vs 75, P = 0.79, respectively). The distributions of patient-reported ECOG were also similar (P = 0.86). Edmonton Symptom Assessment Scale scores for every assessed symptom were similar for different modalities of therapy. Median scores on these tools were also similar regardless of recurrence status or management of relapsed disease (aggressive versus non-aggressive).

CONCLUSION

Survivors with Stage II-IVa thymic malignancies report favourable HUS, VAS and self-reported ECOG with minimal symptom burden. These outcomes may be independent of number and type of initial treatment modalities or management of recurrence.

The European Society of Thoracic Surgeons (ESTS) thymic database

The European Society of Thoracic Surgeons (ESTS) thymic database is a satellite database of the ESTS registry collecting patients with thymic tumors (thymomas, thymic carcinomas and neuroendocrine thymic tumors) among the ESTS Institutions. The database is free of charge for any ESTS member, easily accessible to any ESTS institution, web-based, prospective, periodically maintained and updated. It may serve as an institutional database for the storage of data about patients with thymic tumors at no cost for each participating institution. It may be used by any ESTS member to propose studies using one of the largest thymic databases worldwide. The present review focuses on the history and the development of the ESTS thymic database (retrospective and prospective) and its structure with a particular reference to the concept of the minimum dataset and the Clinical Care Analysis (CCA) box. A brief overview about the role of the ESTS thymic database in the global effort for the new TNM staging system of thymic tumors is also provided. In the supplementary, there are clear instructions to get access to the thymic database using the ESTS official website. The ESTS thymic database represents a powerful tool available to all ESTS members which can be used for studies on the management of these rare tumors.

The expanding role of radiation therapy for thymic malignancies

The role of radiation therapy (RT) in thymic malignancies has long been subject to considerable controversy. The main role for RT is in the setting of adjuvant therapy after surgical tumor resection, especially in advanced or incompletely resected cases. However, recent studies with larger patient numbers and cleaner study populations than previous studies have indicated a potentially clearer than previously assumed benefit after post-operative RT (PORT) even for completely resected patients with earlier stages of thymoma. In marginally resectable patients RT may be used in combination with neoadjuvant chemotherapy to shrink tumors and thereby potentially enable resection. In unresectable patients concurrent or sequential chemotherapy and RT can be employed as the definitive nonsurgical approach. The tendency of thymic tumors to recur in the pleural space highlights the necessity for more effective approaches to identify and treat high risk patients. Experiences in other pleural malignancies may pave the way to novel treatment modalities, for example pleural IMRT. The role of these techniques in thymic malignancies has yet to be determined and is not advisable at the current time outside of a clinical study. As the disease often takes an indolent course with excellent long-term local control (LC) and survival, late toxicities related to radiation of the mediastinum and adjacent organs at risk (OARs) have to be taken into consideration and may jeopardize the benefit patients experience from RT, especially in younger patients with a long-anticipated life expectancy. Radiation techniques, such as intensity modulated RT (IMRT) and proton beam therapy (PBT), have substantially reduced the exposure of OARs to ionizing radiation which is expected to translate into reduced long-term toxicities. Hence, the risk-benefit ratio of RT in early stage thymoma patients may be shifted favorably.

[Surgical Treatment of Refractory Chest Tumors Assisted by Cardiopulmonary Bypass]

背景与目的

回顾性总结体外循环辅助下累及心脏或大血管的难治性胸部肿瘤外科治疗体会。

方法

总结我院2008年1月-2017年5月实施的体外循环下外科手术切除累及心脏或大血管的11例胸部肿瘤患者，分析所有患者的一般情况、临床特征、治疗方法、术后住院时间、并发症及随访结果。

结果

11例患者均在体外循环辅助下手术。肿瘤全部切除者8例，大部分切除者3例，其中1例先行左房内转移性肺平滑肌肉瘤切除，再行右肺中下叶切除术；1例经胸骨正中切口行左肺中央型肺癌切除术；2例同时行肺动脉修补术，3例同时行部分心包切除术，3例同时行肺楔形切除术。所有患者术后症状均得到有效缓解。无院内及术后30天死亡率。3例术后出现肺部感染，于抗生素治疗后恢复。1例淋巴瘤术后6个月复发，1年后死亡；1例心包内纤维肉瘤患者于术后13个月局部复发伴广泛转移，15个月死亡，1例肺平滑肌肉瘤患者于术后15个月发现局部复发灶，予以化疗后缓解。其余8例患者均存活，且计算机断层扫描（computed tomography, CT）检查均未发现明显复发及远处转移。

结论

对于累及心脏或大血管的难治性胸部肿瘤可以实施体外循环辅助下的外科手术治疗，可以提高难治性胸部肿瘤的手术切除率，有效缓解对呼吸、循环功能的影响，明显延长此类患者的生存期。

Clinical features, diagnosis and thoracoscopic surgical treatment of thymic cysts

Background

Thymic cysts are rare benign developmental anomalies and there is no consensus management for thymic cysts. The aim of this study was to disclose the efficacy of perioperative diagnosis for thymic cysts by chest computerized tomography (CT) and to elucidate the surgical procedure by video-assisted thoracic surgery (VATS) in the management of thymic cysts.

Methods

We retrospectively reviewed 108 consecutive thymic cyst patients who underwent VATS at our institution between April 2001 and August 2015. All patients received chest CT preoperatively and underwent VATS treatment. Clinical characteristics, imaging features and surgical exploration were taken into consideration to determine the surgical extent.

Results

Multivariate logistic regression analysis showed that a diameter ≤3 cm [risk ratio (RR) =4.525; 95% confidence interval (CI), 1.027-20.000; P=0.046] and an unenhanced CT value >20 Hounsfield unit (Hu) (RR =7.043; 95% CI, 1.750-28.345; P=0.006) were independent factors of incorrect diagnosis of chest CT. Three different surgical procedures were performed, which included thymectomy (n=49), cyst resection and partial thymectomy (n=46), and extended thymectomy (n=13). No serious postoperative complications were observed. The median follow-up-time was 60.6 months (range, 12.0-168.0 months) with no late complications or recurrences.

Conclusions

A diameter ≤3 cm and an unenhanced CT value >20 Hu were independent factors of incorrect diagnosis of chest CT. VATS is a reliable approach for the surgical resection of thymic cysts. We think that local resection is adequate for simple thymic cysts. However, thymectomy is necessary when there is suspicion of a thymoma or multilocular thymic cyst, and radical thymectomy is advisable for patients with autoimmune diseases.

Multimodality treatment of stage II thymic tumours

BACKGROUND

Complete resection for stage II thymic tumors can be easily accomplished even if the capsula and adjacent mediastinal tissue are macroscopically involved; however, also at this stage, recurrence may occur, particularly for B2, B3 and thymic carcinoma. The criteria for the administration of adjuvant therapy remain controversial and it is unclear whether patients at this stage may benefit from it. We reviewed a series of patients at this stage receiving adjuvant chemo-radiotherapy (chemo-RT) based on histology.

METHODS

Eighty-eight consecutive patients with stage II thymic tumors were reviewed; 59 patients (67%) with B thymoma or thymic carcinoma received adjuvant treatment with mediastinal irradiation (40-55 Gy), chemotherapy (CH) (PAC regimen) or a combination of both.

RESULTS

Complete resection was achieved in all patients. Fifty-four patients (61%) received post-operative chemo-RT, 2 (2%) patients received adjuvant CH only and 3 (3%) post-operative RT only; they all had B2, B3 histology or thymic carcinoma. The median follow up was 107±83 months. 5-year and 10-year survival were 96%±2% and 83.4%±5%. Recurrence was observed in 5 patients (5.7%). Disease-free 5 and 10-year survival was 94%±2% and 92%±3% respectively. Five patients (5.7%) had recurrence.

CONCLUSIONS

The administration of adjuvant chemo-RT to patients with stage II type B thymoma and thymic carcinoma contributes to reduce the recurrence rate and to increase long-term survival.

Prognostic value of immunohistochemical markers in malignant thymic epithelial tumors

BACKGROUND

Thymic epithelial tumors (TET) are rare neoplasms with inconsistent treatment strategies. When researching for molecular pathways to find new therapies, the correlation between specific molecular markers and outcome has only rarely been investigated. The aim of this study was to investigate the correlation between survival, metastatic potential and invasiveness of aggressive subtypes of TET and immunohistochemical markers.

METHODS

Overall survival (OS), disease-free survival (DFS), progression-free survival (PFS) and metastasis-free survival (MFS) of patients with WHO type B2/B3 mixed type thymoma (MT), thymoma type B3 (B3) and thymic carcinoma (TC), undergoing surgery [1998-2013] were determined. Tumor specimens were stained using a tissue microarray (TMA) (CD117, CD5, p63, p40, p21, p27, p53, Bcl-2, Ki67, podoplanin, synaptophysin, PTEN and Pax8). Invasive behavior of primary tumors and the presence of extrathoracic metastases were assessed.

RESULTS

We found in 23 patients included into this study (four MT, ten B3, nine TC) that (I) p21 expression in the cytoplasm significantly correlated with a decrease of OS (P=0.016), PFS (P=0.034) and MFS (P=0.005); (II) MFS was significantly shorter when the combination of p21-low p27-low p53-high was present (P=0.029); and (III) nuclear p27 (P=0.042), Ki-67 (P=0.024) and podoplanin (P=0.05) expression correlated with the presence of extrathoracic metastases.

CONCLUSIONS

The main finding of this study is that cytoplasmic p21 expression negatively influences the outcome of malignant TETs and correlates with metastatic activity. Additionally, selected immunohistochemical markers correlate with the distant metastatic potential of TETs. These results may contribute to the stratification of diagnosis and improvement of treatment strategies for thymic malignancies.

Thymoma and thymic carcinomas

Thymomas (Ts) and thymic carcinomas (TCs) are rare tumours of the mediastinum with an incidence rate of 1.7/million per year in Europe. Histological classification is based on rate of non-malignant-appearing thymic epithelial cells and proportions of lymphocytes (A, AB, B1, B2, B3, and C), while staging system concerns localisation of the involved areas. Surgery is the mainstay of treatment with a 10-year survival of 80%, 78%, 75%, and 42% for stages I, II, III and IV, respectively, with an R0 resection. Radiotherapy has a role in selected cases (stage III patients or R1-2 residual) and platinum-based chemotherapy remains the standard of care for patients with advanced disease. A multimodality approach would be advisable when surgery is not recommended. Since molecular aberrations are poorly understood and few responses are reported, targeted therapies are yet being studied. In this review, we describe key aspects of clinical management for Ts and TCs.

Video assisted thoracic surgery (VATS) for recurrent thymoma

Between 10-30% of patients that undergo a radical operation for thymoma develop a recurrence in a variable range of time. The surgical treatment of thymoma relapses is an established and effective therapeutic approach, particularly for a single intrathoracic recurrence; however, no agreement has been reached on the best surgical approach and the extent of surgical resection, particularly in the most common event of pleural relapses. In the era of minimally invasive approach for most thoracic pathologies, the role of the video assisted thoracic surgery (VATS) approach for thymoma recurrence resection is still unclear and controversial: to date, only few authors have reported in their series a thoracoscopic resection of pleuro-pulmonary relapses, mostly when a single lesion was present. Furthermore, a thoracoscopic approach for mediastinal recurrence has been rarely reported after a previous sternotomy to resect the primary tumor. It is likely that in the future, the role of VATS for thymic recurrence resection will be better defined and extensively studied.

State of the art: diagnostic tools and innovative therapies for treatment of advanced thymoma and thymic carcinoma

In this review article, state-of-the-art diagnostic tools and innovative treatments of thymoma and thymic carcinoma (TC) are described with special respect to advanced tumour stages. Complete surgical resection (R0) remains the standard therapeutic approach for almost all a priori resectable mediastinal tumours as defined by preoperative standard computed tomography (CT). If lymphoma or germ-cell tumours are differential diagnostic considerations, biopsy may be indicated. Resection status is the most important prognostic factor in thymoma and TC, followed by tumour stage. Advanced (Masaoka-Koga stage III and IVa) tumours require interdisciplinary therapy decisions based on distinctive findings of preoperative CT scan and ancillary investigations [magnetic resonance imaging (MRI)] to select cases for primary surgery or neoadjuvant strategies with optional secondary resection. In neoadjuvant settings, octreotide scans and histological evaluation of pretherapeutic needle biopsies may help to choose between somatostatin agonist/prednisolone regimens and neoadjuvant chemotherapy as first-line treatment. Finally, a multimodality treatment regime is recommended for advanced and unresectable thymic tumours. In conclusion, advanced stage thymoma and TC should preferably be treated in experienced centres in order to provide all modern diagnostic tools (imaging, histology) and innovative therapy techniques. Systemic and local (hyperthermic intrathoracic chemotherapy) medical treatments together with extended surgical resections have increased the therapeutic options in patients with advanced or recurrent thymoma and TC.

Radical surgical resection of advanced thymoma and thymic carcinoma infiltrating the heart or great vessels with cardiopulmonary bypass support

Background

Radical surgical resection of advanced thymic tumors invading either the heart or great vessels facing towards the heart is uncommonly performed because of the potential morbidity and mortality. To achieve a complete tumor resection, the use of cardiolpulmonary bypass (CPB) support might be necessary.

Methods

Retrospective analysis of the results in six patients, who underwent radical tumor resection with CBP support.

Results

Mean age was 46 years (27 to 66 years) and five patients were male. Tumor infiltration of the heart or the great vessels was evident in all patients. Five patients underwent induction therapy. Two patients were operated in complete cardioplegic arrest (antegrade cerebral perfusion: n = 1). Arterial cannulation of the ascending aorta (n = 5) or the femoral artery (n = 1) and venous cannulation of the right atrium (n = 4) or the femoral vein (n = 2) were performed. Resection of the left brachiocephalic vein (n = 6), resection of the superior caval vein (n = 2), the ascending aorta (n = 1) and the complete aortic arch with outgoing branches (n = 1) were performed. A macroscopic complete resection (R0/R1) was achieved in five patients, whereas one patient was resected incompletely (R2). In-hospital mortality was 0 %. Three (50 %) patients needed operative revision (hematothorax: n = 2, chylothorax: n = 1). All patients had a complicated postoperative course and developed respiratory insufficiency.

Conclusions

Locally advanced thymoma/thymic carcinoma invading the heart or great vessels can be treated with radical surgical resection alongside with increased perioperative morbidity. The usage of CBP improves the chance of complete tumor resection in selected patients and might lead to a prolonged survival.

Approaching the patient with an anterior mediastinal mass: a guide for clinicians

Anterior mediastinal masses are relatively uncommon, include a wide variety of entities, and often pose a diagnostic challenge for clinicians. In this article, available data is assembled in a clinically oriented manner to develop a structured approach to evaluation of these patients. Attention to age and gender, combined with identification of certain radiographic and clinical characteristics, allows a presumptive diagnosis to be established in most patients. This structure efficiently guides what additional workup is needed.

Non-intubated thoracic surgery-A survey from the European Society of Thoracic Surgeons

BACKGROUND

A survey amongst the European Society of Thoracic Surgeons (ESTS) members has been performed to investigate the currents trends, rates of adoption as well as potential for future expansion of non-intubated thoracic surgery (NITS) performed under spontaneous ventilation.

METHODS

A 14-question-based questionnaire has been e-mailed to ESTS members. To facilitate the completion of the questionnaire, questions entailed either quantitative or multiple-choice answers. Investigated issues included previous experience with NITS and number of procedures performed, preferred types of anesthesia protocols (i.e., thoracic epidural anesthesia, intercostal or paravertebral blocks, laryngeal mask, use of additional sedation), type of procedures, ideal candidates for NITS, main advantages and technical disadvantages. Non-univocal answer to multiple-choice questions was permitted.

RESULTS

Out of 105 responders, 62 reported an experience with NITS. The preferred types of anesthesia were intercostal blocks with (59%) or without (50%) sedation, followed by laryngeal mask with sedation (43%) and thoracic epidural anesthesia with sedation (20%). The most frequently performed procedures included thoracoscopic management of recurrent pleural effusion (98%), pleural decortication for empyema thoracis and lung biopsy for interstitial lung disease (26% each); pericardial window and mediastinal biopsy (20% each). More complex procedures such as lobectomy, lung volume reduction surgery and thymectomy have been performed by a minority of responders (2% each). Poor-risk patients due to co-morbidities (70%) and patients with poor pulmonary function (43%) were considered the ideal candidates. Main advantages included faster, recovery (67%), reduced morbidity (59%) and shorter hospital stay with decreased costs (43% each). Reported technical disadvantages included coughing (59%) and poor maneuverability due to diaphragmatic and lung movements (56%). Overall, 69% of responders indicated that NITS procedures will be likely to increase in the near future.

CONCLUSIONS

Results of this survey, suggest that NITS is already quite widely adopted by ESTS members to perform simple thoracoscopic procedures. A future expanded adoption of this strategy is also hypothesized.

Thymic carcinoma: a cohort study of patients from the European society of thoracic surgeons database

INTRODUCTION

Thymic carcinoma is a rare and aggressive thymic neoplasm. The European Society of Thoracic Surgeons developed a retrospective database collecting patients undergoing resection for thymic tumors from 1990 to 2010.

METHODS

Of 2265 patients with thymic tumors, there were 229 thymic carcinomas. Clinicopathological characteristics were analyzed including age, associated paraneoplastic diseases, stage (Masaoka-Koga), World Health Organization histologic subtypes, type of resection (total/subtotal/biopsy/no resection), tumor size, pre/postoperative treatments, and recurrence. Outcome measures included overall survival (OS), freedom from recurrence, and cumulative incidence of recurrence.

RESULTS

A complete resection was achieved in 140 patients (69%). Recurrence occurred in 54 patients (28%). Five- and 10-year OS rates were 0.61 and 0.37. Five- and 10-year freedom from recurrence rates were 0.60 and 0.43. Cumulative incidence of recurrence was 0.21 (3 yr), 0.27 (5 yr), and 0.32 (10 yr). Survival was better after surgical resection versus biopsy/no resection (p < 0.001), after complete resection versus subtotal resection (p < 0.001), and when using Masaoka-Koga system (stages I-II versus III versus IV) (p < 0.001). The use of multidisciplinary treatments resulted in a survival advantage which was significant in the surgery + radiotherapy group (p = 0.02). Incomplete resection (p < 0.0001) and advanced stage (Masaoka-Koga III-IV) (p = 0.02) had a negative impact on OS at multivariable analysis. Administration of adjuvant radiotherapy was beneficial in increasing OS (p = 0.02).

CONCLUSIONS

The results of our study indicate that patients with thymic carcinoma should undertake surgical resection whenever possible; a complete resection and early Masaoka-Koga stage are independent predictors of improved survival; our results also suggest that postoperative radiotherapy is beneficial in improving survival.

Management of thymic tumors: a European perspective

Thymic tumors are rare mediastinal tumors, which are considered as orphan diseases due to their low prevalence. The most recent histologic classification divides thymic tumors into thymomas, thymic carcinomas (TC) and neuroendocrine thymic tumors (NETT). Until recently, clinical research on thymic tumors has been primarily represented by single-institution experiences usually scattered over a long time period in order to accumulate a sufficient number of patients for clinical analysis. Europe has played a pivotal role in the advancement of the clinical research on thymus in the past years. In the last decade, there has been an increased interest in thymic malignancies in the scientific community. The European Society of Thoracic Surgeons (ESTS), the most representative society of general thoracic surgeons in the world, established a dedicated thymic working group in 2010 with the intent to provide a platform among ESTS members with a specific interest in thymic malignancies. The present review is intended to provide, through the description of the activity of the ESTS thymic working group and its published results, an overview of the European contribution to the thymic research. A brief overview of the state-of-the-art of clinical presentation, diagnosis, staging and histologic classification of thymic tumors is also provided, along with the most recent therapeutic advancements.