JPC SYSTEMIC PATHOLOGY
HEMOLYMPHATIC SYSTEM
April 2018
H-V02

Signalment (JPC #1350931):  Unknown age and gender owl monkey  

HISTORY:  This owl monkey was housed in a cage next to a squirrel monkey

HISTOPATHOLOGIC DESCRIPTION:  Liver:  Diffusely infiltrating portal areas and sinusoids, separating, surrounding and replacing adjacent hepatocytes, and surrounding central veins is an unencapsulated, infiltrative neoplasm composed of round cells arranged in sheets.  Neoplastic cells have variably distinct borders, scant amounts of eosinophilic granular cytoplasm, with a round to oval, vesiculate nucleus and 1 - 3 magenta nucleoli.  The mitotic count averages 1-2 per 40x fields.  Neoplastic cells are frequently within the lumen of blood vessels and sinusoids.  Multifocally there is a moderate amount of single cell necrosis and low numbers of neutrophils.  Diffusely, remaining hepatocytes are distended with one or more round clear vacuoles up to 20 µm in diameter (lipid) that often contain small amounts of pale green-brown granular intracytoplasmic pigment (hemosiderin or bile). 

MORPHOLOGIC DIAGNOSIS:  Liver:  Lymphoma, owl monkey (Aotus trivirgatus), nonhuman primate

ETIOLOGIC DIAGNOSIS:  Herpesviral lymphoma

CAUSE:  Herpesvirus saimiri (Saimiriine herpesvirus 2)

GENERAL DISCUSSION:

PATHOGENESIS:

TYPICAL CLINICAL FINDINGS:

TYPICAL GROSS FINDINGS:

TYPICAL LIGHT MICROSCOPIC FINDINGS:

COMPARATIVE PATHOLOGY:

REFERENCES:

  1. Bailey C, Mansfield K. Emerging and reemerging infectious disease of nonhuman primates in laboratory setting. Vet Pathol. 2010;47(3):462-481.
  2. Bielefeldt-Ohmann H, Barouch DH, Bakke AM, et at. Intestinal stromal tumors in a simian immunodeficiency virus-infected, simian retrovirus-2 negative rhesus macaque (Macaca mulatta). Vet Pathol. 2005;42(2):391-396.
  3. Lerche NW, Simmons JH. Beyond specific pathogen-free: biology and effect of common viruses in macaques. Comp Med. 2008;58(1):8-10.
  4. Merlo J, Tsygankov A. Herpesvirus saimiri oncoprotein Tip and StpC synergistically stimulate NF-kappaB activity and interleukin-2 gene expression. Virology. 2001;279(2):325-338.
  5. Newkirk KM, Brannick EM, Kusewitt DF. Neoplasia and tumor biology. In: Zachary JF, ed. Pathologic Basis of Veterinary Disease. 6th St. Louis, MO: Elsevier; 2017: 318, E-Table 6-2.
  6. Wachtman L, Mansfield K. Viral diseases of nonhuman primates. In: Bennett B, Abee C, Henrickson R, eds. Nonhuman Primates in Biomedical Research: Diseases. San Diego, CA: Academic Press; 2012:7-26.
  7. Westmoreland SV, Mansfield KG. Comparative pathobiology of Kaposi sarcoma-associated herpesvirus and related primate rhadinoviruses. Comp Med. 2008;58(1):31-42.


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