Thymic epithelial tumours – a retrospective analysis of 20 years in a Portuguese pneumology department

Introduction: Thymic Epithelial Tumours (TET) represent a group of rare primary tumours of the mediastinum, and include Thymomas and Thymic Carcinomas. Objectives: Describe demographics, clinical presentation, staging and survival of patients diagnosed with TET; compare our results with current ESMO guidelines for TET (2015). Methods: Retrospective analysis of medical records of patients diagnosed with thymic tumours, followed in our pneumology department, between 1999 and 2019. Results: We identified 30 patients, of which 3 were excluded for not meeting the definition of TET (two were neuroendocrine thymic tumours and one a thymolipoma). Of the remaining 27, 59.3% were males, mean age 64.4±2.28 years. Most patients (85.2%) had no smoking habits and 63% had no significant comorbidities. Previous malignancy was reported in only 11.1%. Auto-immune disorders were present in a third of the patients; of those, 77.7% presented with myasthenia gravis and 11.1% with one of the following: red cell aplasia, thyroiditis, Good syndrome, cerebellar degeneration. Nonspecific respiratory symptoms were present in 55.5%. The most frequent histopathological type, according to the World Health Organisation classification, was B1 (22.2%), followed by AB, B2 and C (18.5% each). Regarding the Masaoka-Koga classification, 29.6% patients were in stage I and another 29.6% in stage IVA. Eighteen patients underwent surgery. 5-year overall survival was 75%, and progression of the disease occurred in 6 cases. Discussion and Conclusions: In comparison to the guidelines, our sample had a higher proportion of males, higher mean age and higher incidence of advanced disease, which resulted in a lower 5-year survival.