SPONTANEOUS RENAL LYMPHOSARCOMA IN A JUVENILE CYNOMOLGUS MONKEY (MACACA-FASCICULARIS)

Spontaneous lymphosarcoma, likely of renal origin, was diagnosed in a naive, juvenile, male cynomolgus monkey (Macaca fascicularis). Histolo gically, renal architecture was effaced by dense infiltrating sheets o f plump cells with indistinct borders and scant amphophilic cytoplasm. Mitoses were uncommon. Similar neoplastic infiltrates were also prese nt in the right renal cortex, one adrenal medulla, the prostate, semin al vesicles, myocardium, and the pulmonary interstitium. Serological t ests were negative for infection with Simian Immunodeficiency Virus (S IV), Simian T-Lymphotropic Virus-1 (STLV-1), and Simian Retrovirus-5.