Universidade Federal Rural da Amazônia. Instituto de Saúde e Produção Animal. Belém, PA, Brazil.Universidade Federal Rural da Amazônia. Instituto de Saúde e Produção Animal. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil / Fundação Oswaldo Cruz. Instituto de Ciência e Tecnologia em Biomodelos. Rio de Janeiro, RJ, Brazil.Universidade Federal Rural da Amazônia. Instituto de Saúde e Produção Animal. Belém, PA, Brazil.Myelolipoma is an unusual benign neoplasm in veterinary medicine. This work intended to report the occurrence of
hepatic myelolipomas in Neotropical primates of the Callimico goeldii species kept in captivity. These cases were
diagnosed during necropsy in a survey on liver neoplasms in the period of 2004 to 2008. Two cases were found in adult
male, and two in adult female animals. The diagnoses were obtained through data analysis of necropsy records, pathological
examination of the cases, and histological confirmation. Three (75%) of the animals showed clinical signs of progressive
weight loss, and two (50%) of them exhibited regional abdominal bloating. The livers had protrusions of pale yellow color
on the surface of all lobes. Histologically, the tumors were formed by mature myeloid tissue with high hematopoietic
cellularity, represented by the megakaryocytes and meroblastic cells and immature erythroblasts. We conclude that nonhuman primates of the Callimico goeldii species might have predisposition for liver myelolipoma, which are neoplasms that
can lead to the failure and destruction of this organ