Caption |
Mammary gland: a mammary duct is markedly ectatic. It contains a large amount of strongly acidophilic proteinaceous fluid and a few slender papillary projections lined by a two cells-thick epithelium where neoplastic cells occasionally pile-up. The occurence of two layers of cells is consistent with myoepithelial and luminal differentiation of neoplastic cells (complex papillary adenoma). Luminal neoplastic cells are cuboidal, small, with indistinct cell borders and a moderate amount of granular acidophilic cytoplasm. The nucleus is central, oval, medium-size and normochromatic. Basal neoplastic cells (arrowheads) are cuboidal, small, with indistinct cell borders, a scant amount of acidophilic cytoplasm and a small hyperchromatic nucleus. There is no evidence of atypia and mitotic rate is low. |
