Mucoepidermoid thymic carcinoma: a challenging mediastinal aspirate.

Primary thymic carcinoma-mucoepidermoid cell (MEC) type is rare and only one report describing the cytologic features of this neoplasm in the metastatic site is described. We describe the cytological features of poorly differentiated carcinoma possibly MEC in a 54-year-old man who presented with cough, weight loss, and puffiness of face for 3 months. The significance of this infrequently encountered neoplasm lies in its potential confusion of origin of the tumor-thymus or metastases from a primary bronchial MEC. Immunocytochemical profile was suggestive of a thymic carcinoma of the MEC type.