Profile of endometriosis in the aging female rhesus monkey

Background. A retrospective analysis was conducted on necropsy records from a large rhesus monkey colony to evaluate the age-related prevalence of endometriosis. Methods. A total of 314 records collected over a 15-year period were analyzed, yielding 66 monkeys with histologically verified endometriosis and 248 control subjects. Results. The analyses demonstrated that the incidence of endometriosis increases progressively across the life span, ultimately impacting 21-45% of aged monkeys over 20 years of age. Conclusions. Because mild disease is often not diagnosed premortem, the endocrine and immune sequelae of endometriosis may be a potential confound in even nonreproductive research with aging primates. Prior research-related events influence the occurrence and severity of endometriosis in these long-lived animals, and specifically could have contributed to the high prevalence of endometriosis in this particular monkey colony.