Abstract

A 47-year-old multiparous female bonobo (Pan paniscus), initially presumed to be post-reproductive, tested positive for pregnancy on a routine urine test. Multiple transabdominal ultrasound evaluations performed under voluntary behavior revealed that the uterus contained a mass of heterogenous tissue which was rapidly increasing in size. Based on a lack of normal fetal development and the mixed ultrasonographic appearance of the uterine tissue, a molar pregnancy was suspected. Molar pregnancies are the most common form of gestational trophoblastic disease.^2,5 Since they are precursors to gestational trophoblastic neoplasia, molar pregnancies are considered to be premalignant disorders.^1,4,5 Treatment options included surgical curettage of the uterine contents, chemotherapy, and ovariohysterectomy.^1,4 Due to the risk of acute blood loss during dilation and curettage and the increased likelihood for metastasis in this aged bonobo, ovariohysterectomy was elected.^1,5 A complete hydatidiform mole was confirmed through elevated human chorionic gonadotropin levels as well as gross and histological examination of the uterus. Although a single case of partial hydatidiform mole was previously documented in a chimpanzee on postmortem examination, to the authors’ knowledge this is the first time a complete molar pregnancy has been reported antemortem in a non-human great ape.³ This case provides support for extending the age range of birth control recommendations and routine pregnancy monitoring of geriatric captive great apes that exhibit active breeding behavior.

Acknowledgments

The authors thank Sarah Christoff, RVT, and Dewey Maddox, CVT, from the Jacksonville Zoo and Gardens as well as James Bailey, DVM, MS, DACVA for assistance with anesthesia. Thank you to William H. Long, MD, and Xujia Annie Song Smith, MD, from North Florida OB/GYN for performing the ovariohysterectomy. The authors greatly appreciate the keepers in the Great Ape and Animal Health Departments of the Jacksonville Zoo and Gardens for their outstanding training skills and daily care for Lorel. The authors also thank the staff of Northwest ZooPath, including Christie Buie for plate layout and Cathy Monogue for data retrieval and to Leroy Brown of Histology Consulting Service for providing histology slide preparation.

Literature Cited

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2.  Cavaliere A, Ermito S, Dinatale A, Pedata R. Management of molar pregnancy. J Prenat Med. 2009;3:15–17.

3.  Debyser IWJ, Soma H, Zwart P. Partial hydatidiform mole in a pregnant chimpanzee (Pan troglodytes). Zoo Biol. 1993;12:299–305.

4.  De Vos M, Leunen M, Fontaine C, De Sutter PH. Successful primary treatment of a hydatidiform mole with methotrexate and EMA/CO. Case Rep Med. 2009;464161.

5.  Sarwar N, Seckl M. Clinical features of molar pregnancies and gestational trophoblastic neoplasia. In: Hancock BW, Newlands ES, Berkowitz RS, eds. Gestational Trophoblastic Disease. 4th ed. International Society for the Study of Trophoblastic Diseases [Internet]. c2015 [cited 2017 March 12]. Available from https://isstd.org/gtd-book/chapter10