Thymic carcinoma developing in a multilocular thymic cyst

Thymic carcinoma developing in a pre-existing thymic cyst has rarely been reported in literature. The diagnosis of this entity in the past has always been established after surgery. We are reporting a case of thymic carcinoma that developed in a preexisting multilocular thymic cyst in an elderly male. The diagnosis was based on imaging findings and confirmed on fine needle aspiration cytology (FNAC).