Diagnosis and treatment of chronic T-lymphocytic leukemia in a spotted hyena (Crocuta crocuta)

Cora L. Singleton, Raymund F. Wack, Tanja S. Zabka, Michael S Kent, R. Scott Larsen

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


Physical examination of an asymptomatic 20-yr-old intact female spotted hyena (Crocuta crocuta) revealed a midabdominal mass. A complete blood count (CBC) revealed peripheral lymphocytosis. Abdominal ultrasonography and laparoscopy confirmed severe splenomegaly. Cytologic examination of a bone-marrow core and histologic examination of spleen and liver biopsy samples revealed neoplastic small lymphocytes. Immunohistochemical staining of liver and spleen samples with the use of leukocyte-specific monoclonal antibodies showed that the neoplastic lymphocytes were immunoreactive to T-lymphocyte CD3 receptor and immunonegative to B-lymphocyte CD79a receptor. The morphology and distribution of neoplastic T-lymphocytes within the spleen, liver, peripheral blood, and bone marrow was most consistent with chronic T-lymphocytic leukemia. Treatment with chlorambucil and prednisone effectively decreased the lymphocyte count, but was associated with thrombocytopenia, which resolved after chlorambucil treatment was temporarily discontinued. Chemotherapy was resumed with a single dose of L-asparaginase, followed by a lower dosage of chlorambucil and continued prednisone. Two years after initial diagnosis, the hyena developed a hemoabdomen and was euthanized. Neoplastic T-lymphocytes were present in spleen, liver, visceral and peripheral lymph nodes, lungs, heart, kidney, adrenal glands, mesentery, intestines, pancreas, brain, and bone marrow.

Original languageEnglish (US)
Pages (from-to)488-491
Number of pages4
JournalJournal of Zoo and Wildlife Medicine
Issue number3
StatePublished - Sep 2007


  • Chemotherapy
  • Crocuta crocuta
  • Immunohistochemistry
  • Leukemia
  • Spotted hyena

ASJC Scopus subject areas

  • Environmental Science(all)
  • Animal Science and Zoology
  • veterinary(all)


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