title: Intracerebral Malignant Plasmacytoma in a Mule Deer (Odocoileus hemionus).
abstract: A wild, mature, gravid female mule deer (Odocoileus hemionus) was presented with marked neurological signs, including abnormal behaviour, circling and incoordination. The animal was humanely destroyed and submitted for diagnostic investigation. Grossly, a well-demarcated, 3 × 3 × 3 cm intracranial mass replaced the left olfactory bulb and frontal lobe. Histologically, there was a highly cellular, infiltrative and unencapsulated neoplastic mass of round cells with eccentrically located nuclei. Neoplastic cells were immunohistochemically labelled for lambda immunoglobulin light chain. Clusters of CD20- and CD79a-positive cells were scattered throughout the tumour and CD3- and Iba1-positive cells diffusely infiltrated the neoplasm. Ultrastructurally, the cytoplasm of the neoplastic cells had prominent rough endoplasmic reticulum with a variable degree of dilation. Histopathological, immunohistochemical and electron microscopical results were diagnostic for a solitary extramedullary plasmacytoma. Intracranial neoplasms are rarely diagnosed in wildlife species, but they should be included in the differential diagnosis for potential causes of central nervous system disease.
authors.affiliation: Utah State Veterinary Diagnostic Laboratory, School of Veterinary Medicine, Utah State University, Logan, UT, USA.
authors.forename: C S
authors.initials: CS
authors.lastname: Clancy
authors.affiliation: Utah Division of Wildlife Resources, Salt Lake City, UT, USA.
authors.forename: A
authors.initials: A
authors.lastname: Roug
authors.affiliation: University of Minnesota Veterinary Diagnostic Laboratory, St Paul, MN, USA.
authors.forename: A G
authors.initials: AG
authors.lastname: Armien
authors.affiliation: Utah State Veterinary Diagnostic Laboratory, School of Veterinary Medicine, Utah State University, Logan, UT, USA. Electronic address: arnaud.vanwettere@usu.edu.
authors.forename: A J
authors.initials: AJ
authors.lastname: Van Wettere
mesh_terms: D000818:Animals; D000835:Animals, Wild; D001932:Brain Neoplasms / Q000473:pathology / Q000662:veterinary*; D003670:Deer; D005260:Female; D010954:Plasmacytoma / Q000473:pathology / Q000662:veterinary*
keywords: intracerebral; mule deer; plasmacytoma