Metastatic cholangiocarcinoma in association with abdominal Cestodiasis in a vervet monkey (Chlorocebus pygerythrus)

Abstract

African green monkey (Chlorocebus pygerythrus) is a non-human primate (NHP) and a pivotal model in biomedical research. Spontaneous neoplasms in NHP are rarely reported and only sporadic descriptions have been published. Herein we describe a unique case of metastatic cholangiocarcinoma with concurrent abdominal cestodiasis in an African green monkey, which presented with respiratory insufficiency and abdominal discomfort. An exploratory laparotomy revealed multiple white-grey masses in the liver and colonic serosa alongside with intra-abdominal parasitic cysts. Histologically, the liver masses were composed of poorly-differentiated epithelial cells that formed dense solid areas and trabeculae. An identical microscopic appearance was observed in the lung and colonic lesions. Immunohistochemically neoplastic cells were strongly positive for anti-CK-7 and negative for anti-Hep-Par1 antibodies, which revealed a cholangiocarcinoma. Interestingly the neoplasm strongly expressed 14-3-3-sigma and E-cadherin. Furthermore the histological characteristics of the parasite larvae were consistent with Mesocestoides spp. To the author´s knowledge, this is the first description of a metastatic cholangiocarcinoma with concurrent abdominal cestodiasis in an African green monkey.