Dendritic cell leukemia in a Golden Retriever.
An 8-year-old castrated male Golden Retriever was evaluated for decreased appetite, lethargy, and labored breathing of 1-week duration. Bilateral pulmonary infiltrates, hepatomegaly, and splenomegaly were present. Results of a CBC revealed marked leukocytosis (62,600/microL; reference interval 4000-15,500/microL) and large numbers of atypical cells (30,700/microL) with abundant cytoplasm. There was no concurrent anemia, neutropenia, or thrombocytopenia. Morphology of the atypical cells was most consistent with a histiocytic origin. Similar cells were identified in bone marrow aspirates, and were morphologically suggestive of the macrophage variant of disseminated histiocytic sarcoma. However, flow cytometry of the abnormal circulating cells revealed CD1c, CD11c, and major histocompatibility complex (MHC) Class II expression without expression of CD11d or lymphoid markers, consistent with myeloid dendritic antigen-presenting cells. At necropsy, the splenic architecture was effaced by neoplastic histiocytes that were also infiltrating lung, liver, an abdominal lymph node, myocardium, an bone marrow. Immunohistochemistry of the splenic neoplastic cells confirmed dendritic cell origin (CD1c+, CD11c+, MHC II+, no expression of CD11d and lymphoid markers). To the authors' knowledge, this is the first report of canine dendritic cell leukemia-in this instance accompanied by marked tissue infiltration.
Department of Veterinary Pathobiology, Oklahoma State University, Center for Veterinay Health Sciences, Stillwater, OK 74078, USA. robin.allison@okstate.edu
Robin W
RW
Allison
Jill D
JD
Brunker
Melanie A
MA
Breshears
Anne C
AC
Avery
Peter F
PF
Moore
Verena K
VK
Affolter
William
W
Vernau
D000818:Animals; D001853:Bone Marrow / Q000473:pathology; D003713:Dendritic Cells; D004283:Dog Diseases / Q000097:blood / Q000145:classification* / Q000473:pathology; D004285:Dogs; D007938:Leukemia / Q000097:blood / Q000145:classification / Q000662:veterinary*; D008168:Lung / Q000473:pathology; D008297:Male; D013154:Spleen / Q000473:pathology