Parotid Salivary Gland Basal Cell Adenocarcinoma in a Big-eared Opossum (Didelphis aurita)

Summary The opossum (family Didelphidae) is a marsupial endemic to the Americas. Apart from the South American short-tailed opossum ( Monodelphis domestica ) and the Virginia opossum ( Didelphis virginiana ), there is considerable lack of knowledge about the health and diseases of most opossum species. Among these, the big-eared opossum ( Didelphis aurita ) is found in Argentina, Brazil and Paraguay. Natural and experimental studies have shown this species to be susceptible to infectious agents with zoonotic potential and the animals may play a role in transmission of such agents. However, neoplasia appears to be uncommon in this species. We describe the gross, microscopical and immunohistochemical features of a parotid salivary gland basal cell adenocarcinoma in a free-living big-eared opossum. This case represents the first report of salivary gland neoplasia in opossums.