Aspiration cytology of carcinoid tumor of the breast. A case report.

A primary carcinoid breast tumor was evaluated by fine needle aspiration cytology in an 87-year-old female. The subsequent operative material contained a tumor with the typical histopathologic features of carcinoid tumors in other sites; thorough evaluation of the patient did not reveal carcinoid lesions elsewhere in the body. The tumor contained argyrophil-positive cytoplasmic granules on light microscopy. The cytomorphology of this tumor contains features helpful in identifying it on aspiration cytology material. The differential diagnosis with fine needle aspiration cytology of other breast tumors is discussed.