title: Multicentric lymphoma in a giant anteater (Myrmecophaga tridactyla).
abstract: Neoplastic disease is not well documented in giant anteaters. This report describes a disseminated lymphoma in an adult male giant anteater (Myrmecophaga tridactyla) from the City Zoo of Curitiba, State of Paraná, Brazil. No clinical signs were noticed before its death, except for a slight inappetence. At postmortem examination, pale white to yellow, variably sized nodules infiltrated the heart, liver, and intestinal lymph nodes. Histologically, two distinct cell populations were present in the nodular lesions: one characterized by smaller cells, primarily lymphocytic in nature, and another characterized by larger rounded cells with loose chromatin and frequently indented nuclei resembling histiocytes. Giant binucleated cells were occasionally observed. Mitotic figures numbered 2-3 mitotic figures/x400 field. Both cellular populations presented with moderate pleomorphism, large nuclei, a high nucleus-to-cytoplasm ratio, distinct nucleoli, and coarse nuclear chromatin. The neoplasia was classified as a form of multicentric lymphohistiocytic lymphoma (Rappaport Classification) and as an intermediate grade lymphoma (National Cancer Institute Working Formulation).
authors.affiliation: Veterinary Hospital, Laboratory of Veterinary Pathology, Universidade do Contestado, R. Roberto Elhke, 85, Centro, Canoinhas., SC, CEP 89460-000, Brazil. jabotrix@hotmail.com
authors.forename: Adrien W D
authors.initials: AW
authors.lastname: Sanches
authors.forename: Pedro R
authors.initials: PR
authors.lastname: Werner
authors.forename: Tereza C C
authors.initials: TC
authors.lastname: Margarido
authors.forename: Jose R
authors.initials: JR
authors.lastname: Pachaly
mesh_terms: D000818:Animals; D017809:Fatal Outcome; D006338:Heart Neoplasms / Q000473:pathology / Q000662:veterinary*; D008113:Liver Neoplasms / Q000473:pathology / Q000662:veterinary*; D008198:Lymph Nodes / Q000473:pathology*; D008223:Lymphoma / Q000662:veterinary*; D008297:Male; D004490:Xenarthra