Sebaceous Carcinoma of the Breast: Fact or Fiction? A Case Report and a Review of the Literature.

Previously considered an exceedingly rare entity, sebaceous carcinoma of the breast is now regarded in the World Health Organization 2019 classification as a "special histopathological pattern" of invasive breast carcinoma of no special type. . In this article, we report the case of a fine needle aspiration cytology and the histopathological features of a breast carcinoma with clear-cut morphological features suggesting sebaceous differentiation, but showing no positive staining with the anti-adipophilin antibody. A morphologically clear-cut sebaceous differentiation is not invariably associated with adipophilin positivity; moreover, in breast carcinoma, adipophilin positivity does not automatically imply sebaceous differentiation. At present, immunomorphological evidence for the recognition of sebaceous carcinoma as a "special type" breast carcinoma subtype is too weak.