ECTOPIC THYMOMA MIMICKING DIFFUSE PLEURAL MESOTHELIOMA - A CASE-REPORT

A case of ectopic thymoma of the pleura with a particular growth patte rn mimicking diffuse pleural mesothelioma is reported. Diagnostic imag ing showed that the pleural tumor encased the entire left lung. The sp ecimen biopsied from the tumor was composed of lymphocytes and epithel ial cells, consistent with the mixed type of thymoma. The autopsy foun d no evidence of a mediastinal tumor. An involuted thymus was found in the parietal pleural tissue adhered to the apex of the left lung. The thymoma was thought to originate from the ectopic thymic tissue in th e parietal pleura, as a lesion independent from the primary mediastina l thymoma, and spread along the pleura like diffuse mesothelioma. Copy right (C) 1998 by W.B. Saunders Company.