title: Lipid-rich carcinoma of the mammary gland in a cat.
abstract: A 1.5-year-old female, intact, clinically healthy cat presented for a subcutaneous mass of the ventral abdomen. Surgical excision and microscopic examination of the mass were performed. Histologically, this was a discrete, unencapsulated, multilobular, expansile mass, which compressed the surrounding normal mammary tissue. Lobules were composed of tubuloacinar structures formed by atypical round to polygonal cells, which contained foamy to microvacuolated cytoplasm and variably sized, intracytoplasmic, distinct vacuoles causing nuclear peripheralization. Neoplastic cells demonstrated intense and diffuse immunoreactivity for cytokeratin and lacked immunoreactivity for vimentin. The vacuolar contents stained positively with Oil RedO and negatively with periodic acid-Schiff and Alcian blue stains. Histomorphologic, histochemical, and immunohistochemial analysis support a diagnosis of lipid-rich mammary carcinoma. This is the first report of a cat with a lipid-rich variant of mammary carcinoma.
authors.affiliation: Colorado State University, Pathology Building, 1619 Campus Delivery, Fort Collins, CO 80523, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Kamstock
authors.forename: R
authors.initials: R
authors.lastname: Fredrickson
authors.forename: E J
authors.initials: EJ
authors.lastname: Ehrhart
mesh_terms: D000818:Animals; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism / Q000473:pathology / Q000601:surgery / Q000662:veterinary*; D002371:Cat Diseases / Q000473:pathology*; D002415:Cats; D005260:Female; D007150:Immunohistochemistry / Q000662:veterinary; D007633:Keratins; D050356:Lipid Metabolism; D015674:Mammary Neoplasms, Animal / Q000378:metabolism / Q000473:pathology* / Q000601:surgery
chemical_list: D007633:Keratins