Combined Thymic Epithelial Neoplasms – a Review

Abstract

Thymic epithelial neoplasms are the most common tumors of thymic origin but are overall rare in the general population. Their morphologic diversity, ranging from low grade to overtly malignant lesions, along with various histologic growth patterns make them a diagnostically challenging group of tumors. Very occasionally, thymomas and thymic carcinomas may develop in combination with other benign or malignant lesions of thymic origin, further complicating the diagnostic process. The focus of this review lies on the spectrum of thymic epithelial tumors that present with other thymic lesions in the same tumor mass, such as multilocular thymic cysts, neuroendocrine neoplasms, lymphomas, and germ cell tumors among others. Awareness of the existence of such unusual tumors may not only aid in their diagnosis but may also have implications for prognostic and therapeutic purposes.

Evaluation of the effect of PET/CT Fluorodeoxyglucose inclusion on mortality and survival in operated thymoma patients

“…Despite the increasing use of PET-CT in the planning of staging and treatment strategies [25], there are not enough studies to define its role in the histological classification of thymoma and predicting mortality [14]. Yanarateş et al [26] showed that although PET-CT could not distinguish the histological sub-types of thymic epithelial tumors (TET), it was useful in the differentiation of benign and malignant anterior mediastinal masses.…”

“…Despite the increasing use of PET-CT in the planning of staging and treatment strategies [25], there are not enough studies to define its role in the histological classification of thymoma and predicting mortality [14]. Yanarateş et al .…”

“…Since knowing the histological sub-type before surgery may affect treatment strategies, it is important to distinguish between early and advanced-stage tumors histologically and radiologically [14,15].…”

Primary germ cell tumours of the mediastinum: A review with emphasis on diagnostic challenges

“…Fourthly, PMSEMs in particular show positive immunohistochemical markers, which are also positive in other neoplasias, such as CD117 in rare thymomas and most thymic carcinomas 183 or melanomas, D2‐40 in lymphatic or mesothelial neoplasms 184,185 and TdT in lymphoblastic lymphomas 21,186,187 . Furthermore, rare synchronous PMSEMs and thymic neoplasms have been described 188–191 . For pure PMTERs, the main differential diagnosis encompasses bronchiogenic cysts 192,193 and multilocular thymic cysts (MTCs) 84,194 .…”

“…21,186,187 Furthermore, rare synchronous PMSEMs and thymic neoplasms have been described. [188][189][190][191] For pure PMTERs, the main differential diagnosis encompasses bronchiogenic cysts 192,193 and multilocular thymic cysts (MTCs). 84,194 There is also the possibility of a mixed PMTER with MTC.…”