Sebaceous carcinoma of the breast in a patient with a pathogenic BRCA2 (886delGT) mutation - focus on histopathologic and immunohistochemical features.

Sebaceous carcinoma of the breast (SCB) is a rare variant of ductal carcinoma arising within the mammary gland and containing at least 50% of malignant cells with sebaceous differentiation. Only 11 cases that adjust to the criteria delineated in the WHO classification have been published in the English literature, to the best of our knowledge. Here, we present the first SCB arising in the context of a deleterious BRCA2 mutation, focusing on the histopathologic and immunohistochemical features of this exceedingly rare tumor.