Record review of baboons with histologically confirmed endometriosis in a large established colony

• Published in: Journal of medical primatology 2003-02, Vol.32 (1), p.39-47
• Main Authors: Jr Dick, E.J., Hubbard, G.B., Martin, L.J., Leland, M.M.
• Format: Article
• Language: English
• Subjects: Age of Onset; animal model; Animals; disease; Disease Models, Animal; Endometriosis - veterinary; Female; Monkey Diseases - epidemiology; non-human primates; Papio; Pregnancy; reproduction; Reproductive History
• ISSN: 0047-2565; 1600-0684
• DOI: 10.1034/j.1600-0684.2003.00008.x

: Spontaneous endometriosis was diagnosed in 43 baboons over a 14‐year period. Thirty‐seven have died; five remain alive; one was sold and lost to follow‐up. The average age at diagnosis was 17.2 years; 29 (67%) were between 12 and 21 years of age. Fifteen (35%) were diagnosed by biopsy and received surgical excision of the endometriotic tissue; four of these were identified during caesarian section, confirming one prior report of endometriosis in pregnant animals. Twenty‐eight (65%) were diagnosed at or shortly preceding necropsy. When diagnosed by a palpable abdominal mass, there was a significantly greater likelihood the animal died or was killed as a result of complications of endometriosis. When diagnosis was at necropsy, there was a significantly greater likelihood that the animal died from causes unrelated to endometriosis. Early identification with surgical removal appears to provide a benefit for both survival and delivering offspring after diagnosis. In twenty‐one baboons (49%), endometriosis affected multiple sites within the peritoneal cavity. In the remaining baboons, lesions were more localized. Ovarian involvement was seen in sixteen (37%) of these baboons. This paper is the first to describe significant ovarian involvement in baboons, previously considered a limitation of the usefulness of this species as an animal model. We also describe the first reported endometriosis seeding of an abdominal surgery scar in a baboon. Many of these baboons were middle aged, had few or no offspring, or had evidence of a long duration of uninterrupted menstrual cycles, consistent with risk factors for women. Endometriosis was an incidental finding in 17 (40%) of these baboons, consistent with previous reports of minimal endometriosis as a common asymptomatic finding in baboons and in women. Overall, endometriosis in baboons presents a spontaneously occurring animal model that shares important features with the disease in women and the rhesus macaque.