Thymic Carcinoma: A Review

Abstract

The diagnosis of thymic carcinoma may pose significant problems not necessarily in the histopathological diagnosis but rather in assigning the thymus as specific origin. Often the tissue available for interpretation is obtained via a mediastinocopic biopsy, which raises two different issues -minimal tissue and lack of specific features to make a carcinoma of thymic origin. In addition, if to that conundrum we add that there is no magic immunohistochemical stain that will unequivocally lead to the interpretation of thymic carcinoma, then we are left with a true clinical-radiological-pathological correlation. In this review, we will highlight some of those challenges that diagnostic surgical pathologists may encounter in the histopathological assessment of thymic carcinoma as well as in the staging of these tumors.

Immunotherapy in thymic epithelial tumors: tissue predictive biomarkers for immune checkpoint inhibitors

“…Furthermore, some TMs, such as metaplastic TM or micronodular TM with lymphoid stroma, show histopathological features that do not fit well with the most common histotypes and so they are classified separately. Finally, more than one histological subtype defines mixed cases of TM and the diagnosis should list the predominant pattern followed by any minor components in 10% increments, except for type AB TM which is considered a distinct TM subtype (Figure 1) [27][28][29]. TC is a very rare mediastinal tumor characterized by morphological features of obvious malignant biological behavior and with peculiar immunophenotypic expression of CD5 and CD117 (c-kit), unlike conventional carcinomas of other anatomical sites.…”

“…TC is a very rare mediastinal tumor characterized by morphological features of obvious malignant biological behavior and with peculiar immunophenotypic expression of CD5 and CD117 (c-kit), unlike conventional carcinomas of other anatomical sites. Several histological types of TC are recognized ( Figure 1 ) [ 6 , 30 ]. TNENs are very rare thymic neoplasm accounting for 2–5% of all thymic tumors and they are currently classified just like their pulmonary counterpart, with the same nomenclature and the same diagnostic criteria (mitotic index/2 mm 2 , presence/absence of necrosis and cytomorphological features) of lung neutrophil extracellular traps (NETs) and neuroendocrine carcinoma (NECs) [ 31 ].…”

Thymic Adenocarcinoma With Metastasis to the Left Orbit: A Case Report

“…Primary thymic adenocarcinomas (TAdCas), which are a subtype of thymic epithelial tumors (TETs), are exceptionally rare and thymic enteric-type adenocarcinoma (AdCa) has recently been proposed as a distinct pathological entity [3]. Its diagnosis may have considerable difficulty due to its lack of specific diagnostic features, requiring clinical, radiological and histopathological correlations [4].…”