Large Cell Anaplastic B-Cell Lymphoma, Plasma Cell Myeloma, and Other Causes of Mortality in Golden Monkeys (Cercopithecus mitis kandti) from the Virunga Volcanoes
The golden monkey, an endangered subspecies of the blue guenon (Cercopithecus mitis), is limited to montane bamboo forests of the Virunga volcano chain of Rwanda, Uganda and the Democratic Republic of Congo, sympatric with the endangered mountain gorilla (Gorilla beringei beringei). Golden monkeys are habituated for tourist viewing in the Parc National du Volcans in Rwanda. Population health monitoring by the Mountain Gorilla Veterinary Project, Inc., includes postmortem examinations.
Six golden monkeys have been examined postmortem. One older adult female found moribund in a farmer’s field had multiple enlarged cervical, mediastinal, splenic, pancreatic and sublumbar lymph nodes. There was marked pericardial effusion and pulmonary consolidation. The calvarium had several soft red foci with underlying thickening of the dura. All the above organs, plus liver and pancreas, were infiltrated by a population of large, pleomorphic, neoplastic “round cells.” The diagnosis of multicentric, anaplastic, large B-cell lymphoma was made based on histologic appearance and immunohistochemical staining pattern. The monkey also had marked sparganosis. An adult male had an infected head wound with extension, via cellulitis and phlebitis, to embolic pneumonia and epicarditis and also had plasma cell myeloma characterized by marked, often atypical, plasma cell infiltration of lymph nodes, bone marrow, spleen, heart, salivary glands and adrenal. A third golden monkey was extremely emaciated and had a large subcutaneous and intramuscular abscess and evidence of sepsis. The other three monkeys died from trauma: two from human interactions and one from entanglement in vegetation.