EP1.15-22 Primary Epithelial - Myoepithelial Carcinoma of the Lung with Unexpected Aggressive Onset

Abstract

consistent with tuberculosis. Further work-up did not reveal presence of tumor elsewhere ascertaining a primary lung origin. Patient was started on anti-tubercular therapy and adjuvant radiotherapy/chemotherapy was not given. Patient is currently on follow-up Conclusion: From the limited numbers reported, primary pulmonary HCCCs appear to be indolent slow growing neoplasms with an excellent outcome after surgical excision. The differential diagnoses include the commoner squamous cell carcinomas with clear cell change, clear cell adenocarcinomas, mucoepidermoid carcinomas, metastatic clear cell renal cell carcinoma, and myoepithelial neoplasms. Knowledge of its typical histomorphology aided by prudent immunohistochemistry and demonstration of EWSR1 gene rearrangement or more specifically, EWSR1:ATF1 fusion transcripts should lead one towards the correct diagnosis.