Aspiration biopsy in a case of apocrine adenocarcinoma with foam cells (myoblastomatoid or histiocytoid adenocarcinoma).

We found only one report of a case of apocrine adenocarcinoma with foamy cells diagnosed by aspiration biopsy. Herein, we describe a second case with cytologic, histologic, and immunohistochemical findings and discuss the differential diagnosis of foamy cells on aspiration smears obtained from mammary nodules.