Fine needle aspiration cytology of pleomorphic lobular carcinoma of the breast. Duct carcinoma as a diagnostic pitfall.

Pleomorphic lobular carcinoma (PLC) of the breast is a subtype of lobular carcinoma of the breast that is well recognized in the surgical pathology literature. Fine needle aspiration (FNA) recognition of this subtype is important, for the subtype characteristically pursues an aggressive clinical course as compared to the classic lobular carcinoma of the breast. The cytologic literature on this entity is nonexistent. We describe the FNA findings in a series of four cases of PLC diagnosed retrospectively, discuss the cytologic features that are useful in the recognition of this entity and the diagnostic pitfalls, and propose classifying these tumors as a high (poor) nuclear grade variant of lobular carcinoma, analogous to the grading scheme in use for aggressive ductal carcinomas.