Leishmania spp. in Perianal Adenoma in a Dog: A Case Report.

The coexistence of Leishmania and neoplasia is rarely reported in humans or animals. An 11-year-old intact male mixed-breed dog was presented with a well-demarcated perianal nodule. Cytologic and histopathologic examinations were consistent with the diagnosis of perianal gland adenoma with the presence of Leishmania amastigotes. The dog was considered to be in leishmaniasis stage C (clinically diseased) based on clinical signs, laboratory findings, and serological status. A novel finding in this case report was the presence of Leishmania within the perianal adenoma, probably resulting from an atypical dissemination of the parasites.