Uterine angioleiomyoma in an African green monkey (Chlorocebus aethiops sabaeus).

A uterine neoplasm was observed, as an incidental finding, during post-mortem examination of a 26-year-old female multiparous African green monkey (Chlorocebus aethiops sabaeus). The intramural, expansile, 2 to 3 cm well-demarcated, dark-red, nodular neoplasm was located on the anterior uterine body (corpus) wall. The mass was examined by light microscopy and by immunohistochemistry. The mass was confirmed as a cavernous uterine angioleiomyoma (syn. vascular leiomyoma) characterized by abundant intratumoural vasculature lined by Factor VIII-positive endothelial cells and surrounded by smooth muscle actin-positive cell proliferations. Angioleiomyoma sharing the characteristics of intramural human cavernous uterine angioleiomyoma should be considered in the differential diagnosis of uterine tumours in non-human primates.