Spontaneous Peritoneal Malignant Mesothelioma in a Geriatric Japanese Macaque (Macaca fuscata)

Experimental Animals. Vol. 56 (2007) , No. 2 155-159 [Link]

Jyoji YAMATE1), Akitada TOMITA1), Mitsuru KUWAMURA1), Fusako MITSUNAGA2) and Shin NAKAMURA2)

1) Laboratory of Veterinary Pathology, Life and Environmental Sciences, Osaka Prefecture University
2) Molecular Biology Section, Department of Cellular and Molecular Biology, Primate Research Institute, Kyoto University


A 28.5-year-old female Japanese macaque (Macaca fuscata) was euthanatized because of abdominal distension due to severe ascites. Nodular lesions of varying sizes up to 5 mm in diameter were distributed diffusely on the surface of the omentum, mesentery and parietal peritoneum. No neoplastic masses were detected in any visceral organ. The nodules were composed of proliferation of mono- or multi-layered epithelial-like cells occasionally showing papillary growth and sheets of small round or polygonal cells. Signet ring-like cells and tubular structures were occasionally present. Neoplastic cells were strongly positive to cytokeratin, and occasionally to vimentin. Based on gross and histopathological findings, this tumor was diagnosed as an epithelial type of peritoneal malignant mesothelioma, the first reported case in the non-human primates.

Keywords: Japanese macaque, peritoneal malignant mesothelioma, signet ring-like cell