Polycystic Ovary Syndrome with Endometrial Hyperplasia in a Cynomolgus Monkey (Macaca fascicularis)

Abstract

A 13-year-old, obese, female cynomolgus monkey ( Macaca fascicularis) was observed in a 5-year neurobehavioral study and was humanely euthanatized for experimental purposes. During this observational study, the monkey was noted to ovulate only rarely (0–3 times a year), with a prolonged menstrual cycle length (up to 161 days), hyperandrogenism (androstenedione area under the curve in response to adrenocorticotropic hormone up to 27.64 ng/ml), and hyperinsulinemia (fasting insulin up to 65.85 μIU/ml). This animal's body mass index was 65.46 kg/m2, with central obesity. On postmortem examination, the uterus was moderately enlarged, with an eccentric lumen and a broad-based endometrial polyp that consisted of complex glandular hyperplasia with atypia. Both ovaries contained many 2- to 3-mm follicles, without any corpora lutea. A diagnosis of polycystic ovary syndrome was made based on the clinical history, endocrinology, and gross and histopathologic findings.