Skin with focal epidermal ulceration and an underlying unencapsulated, dense subareolar proliferation. The lesion is composed of haphazardly arranged, closely packed tubular and glandular structures of varying caliber. These structures are embedded within a dense, sclerotic fibrous stroma, imparting a pseudoinfiltrative appearance. Several of the associated ducts and glandular spaces exhibit cystic dilation and contain inspissated eosinophilic secretions. These glandular structures are lined by a benign biphasic cell population: an inner layer of cuboidal to columnar epithelial cells and an intact outer layer of myoepithelial cells. There is no evidence of cytologic atypia, increased mitotic activity, or malignancy.
Nipple biopsy.
Partially skin covered soft tissue fragment measured 1x0.8x0.7 cm, totally embedded.
Nipple biopsy: