Etiology: Adenocarcinomas arise from the glandular epithelium of the mammary tissue.
Incidence: The incidence of mammary adenocarcinoma is common.
Clinical Signs: Mammary adenocarcinomas may be located nearly anywhere in the subcutaneous region due to the extensive distribution of mammary tissue in the mouse (A.).
Pathology: Mammary tumors are usually large, soft, fleshy, well vascularized and may contain necrotic tissue and/or blood-filled cysts. Histologically, mammary adenocarcinomas are often highly pleomorphic with a loss of alveolar differentiation (B.). They often contain variably sized cystic structures lined by pleomorphic to anaplastic acinar cuboidal epithelium (C.) and can be encapsulated or unencapsulated .
Diagnosis: Diagnosis can be made upon necropsy and histopathologic examination of tissue.
1. Pathology Of The Mouse. 1 ed1999, 2850 Oak Grove Road, Vienna, IL, 62995: Cache River Press