Thymoma/Thymic Carcinoma

Abstract

Primary epithelial neoplasms, namely thymomas, comprise the bulk of epithelial thymic tumors in the anterior mediastinum. However, thymic carcinomas are also well known to occur as primary thymic epithelial tumors. These two neoplasms appear to arise de novo and have been regarded as two entirely separate entities. Nevertheless, in unusual circumstances it is possible to observe the occurrence of these two well known histopathologic patterns in the same tumor. Whether one neoplasm—thymoma—gives rise to another more aggressive tumor—carcinoma—remains an unresolved puzzle. However, it is logical to assume that since the two tumors are observed in continuity, this particular phenomenon may represent a spectrum of lesions that go from the conventional thymoma to another more aggressive neoplasm such as thymic carcinoma. Our experience with such cases highlights the importance of proper sampling when dealing with thymic epithelial neoplasms and the risk of attempting to asses such tumors with a limited biopsy or aspiration cytology specimens.

The opinions herein contained are the private views of the author and are not to be construed as the official views of the department of the Air Force or the Department of Defense.