Endometrial Ossification: An Unusual Cause of Infertility

Endometrial ossification, a rare but well recognized phenomenon in uterus, is the presence of bone in endometrium. It is an uncommon entity related to secondary infertility following an abortion. It is of paramount importance for the pathologists to recognize the non neoplastic nature of this condition to avoid making erroneous diagnosis of malignant mixed mullerian tumor of the uterus. Removal of these bony bits leads to spontaneous conception. We are describing a case of endometrial ossification in a 28 years old female, presented with menorrhagia and secondary infertility. Endometrial Ossification: An Unusual Cause of Infertility key Words: Endometrium, Osseous metaplasia, Infertility Case report fragmented endometrial tissue which was predominantly composed of tubular glands with scanty stroma. The osteoid tissue which was mainly composed of the trabeculae of woven bone was present surrounding the endometrial tissue. The endometrial glands did not show any secretory activity. Further examination did not reveal any granuloma, inflammatory reaction, necrosis or the products of conception [Table/Fig-2] and [Table/Fig-3]. The histological diagnosis of osseous metaplasia of the endometrium was made. DISCUSSION Ossification of the endometrium is a rare but well recognized phenomenon in the uterus, which is described by various other names such as ectopic intrauterine bone, heterotopic intrauterine bone and endometrial ossification. Other sites of ossification in the female genital tract are the vagina, the ovary and the cervix [1-7]. Endometrial ossification usually presents as dyspareunia, menstrual irregularities, pelvic pain, vaginal discharge and secondary infertility. Our patient also presented with secondary infertility and menorrhagia. Endometrial ossification has also been reported as a rare cause of primary infertility [2]. The cause of infertility due [Table/Fig-1]: Ultra-sonography showing intracavitary calcification in the form of densely echogenic band P at ho lo g y s ec tio n Manisha Makkar et al., Endometrial ossification www.jcdr.net Journal of Clinical and Diagnostic Research. 2011 June, Vol-5(3): 613-615 614 to endometrial ossification, is either increased prostaglandin production as proposed by Marcus et al [8], or its action as an intrauterine contraceptive device. The aetiopathogenesis of endometrial ossification has been described by many theories; metabolic disorders such as hypercalcaemia, hypervitaminosis D or hyperphosphataemia and chronic endometrial inflammation such as endometritis or pyometra; persistant stimulation of the endometrium by oestrogen; osteogenesis in the surrounding endometrium which is promoted by retained foetal bones; the dystrophic calcification of retained and necrotic tissue. The most recent and accepted theory is the metaplasia of the endometrial stromal cells, usually fibroblasts, which change to osteoblasts and thus produce bone in the endometrium [1],[3],[8]. A previous history of abortion is present in most of the reported cases, with osseous changes in the endometrium. Usually the reproductive age group is involved, with a history of first trimester abortion. These patients resume the normal menstrual cycle in the post abortive period, as was seen in our case. The time interval between the antecedent abortion and the discovery of the endometrial ossification varies from 8 weeks to 14 years in the reproductive age group. In our case, the time interval was 6 years from the abortion, as compared to the history of 37 years from the abortion, which was described by Shimazu and Nakayama in a 62 years old woman [4],[9]. Intrauterine contraceptive device, malignant mixed mullerian tumour, endometrial tuberculosis and retained foetal tissue are the common differential diagnoses for the bone in the uterus, as was seen in our case. Before classifying the heterologous tissue as benign, the pathologist should exclude the possibility that the tissue in question is not a deceptively bland, appearing component of a malignant mixed mullerian tumour or an adenosarcoma. The removal of the heterotopic tissue is expected to restore the fertility, as our case demonstrated, with good endometrial response to the cyclical stimulation [10]. Physicians should also be aware of osseous metaplasia in the differential diagnosis of patients with uncertain history, who present with a sonographic image resembling an intrauterine contraceptive device [3], [4]. Endometrial tuberculosis should be ruled out, as it is a common cause of infertility in Indian females and can sometimes cause calcification and subsequent ossification in the endometrium. Retained foetal tissue is also an important differential diagnosis for osseous metaplasia. The absence of surrounding tissue reaction and endochondral ossification may differentiate osseous metaplasia from the retained foetal tissue [4]. In the past, a series of dilatation and curettage was done to remove the bone from the endometrium, as a vigorous single curettage may lead to synechiae formation. However, recent studies recommend the complete removal of the bony spicules from the endometrial cavity hysteroscopically under ultrasonic guidance [11]. Oestrogens have a controversial role in this condition, as these can themselves cause endometrial ossification by promoting osteogenesis. As the endometrium has a high capacity for proliferation and as the endogenous hormone levels in a regularly menstruating woman are sufficient for its proliferation, this approach is unlikely to be practical [4],[5]. CONCLUSIONThis case report highlights endometrial ossification as a veryrare and peculiar cause of infertility. Fertility and spontaneousconception can be restored by the complete removal of the bonyspicules from the endometrial cavity. Endometrial ossification is animportant differential diagnosis of the malignant mixed mulleriantumour of the uterus. So, clinicians and pathologists should beaware of this entity in order to avoid an erroneous diagnosis. REFERENCES[1] Bhatia NN, Hoshiko MG. Uterine osseous metaplasia. Obstet Gynecol1982; 60:256-259.[2] Shroff CP, Kudterkar NG, Badhwar VR. Endometrial ossification-reportof three cases with literature review. Indian J Pathol Microbiol 1985;28:71-74.[3] Acharya U, Pinion SB, Parkin DE, Hamilton MP. Osseous metaplasiaof the endometrium treated by hysteroscopic resection. Br J ObstetGynaecol 1993; 100:391-392.[4] Bahneci M, Demirel LC. Osseous metaplasia of the endometrium:a rare cause of infertility and its hysteroscopic management. HumReprod 1996; 11:2537-2539.[5] Cayuela E, Perez-Medina T, Vilanova J, Alejo M, Capadas P. Trueosseous metaplasia of the endometrium: the bone is not from a fetus.Fertil Steril 2009; 91:1293-1294.[6] Bedaiwy MA, Goldberg JM, Biscotti CV. Recurrent osseous metaplasiaof the cervix after loop electrosurgical excision. Obstet Gynecol 2001;98:968-970.[7] Campo S, Campo V, Zannoni GF, Gambadauro P. Simultaneousovarian and endometrial osseous metaplasia: a case report. J ReprodMed 2007; 52:241-242.[8] Marcus SF, Bhattacharya J, Williams G. Endometrial ossification acause of secondary infertility. Am J Obstet Gynaecol 1994; 170:1381-1383.[Table/Fig-2]: Photomicrograph showing endometrial tissue with frag-ment of woven bone (H and E; x 40)[Table/Fig-3]: Photomicrograph showing woven bone along with nor-mal endometrial tissue (Masson Trichrome; x 40) www.jcdr.netManisha Makkar et al., Endometrial ossification Journal of Clinical and Diagnostic Research. 2011 June, Vol-5(3): 613-615615[9] Shimizu M, Nakayama M. Endometrial ossification in a postmenopausalwoman. J Clin Pathol 1997; 50:171-172.[10] Sherman ME, Mazur MT, Kurman RJ. Benign diseases of endometrium.In: Kurman RJ ed. Blausteins Pathology of the Female Genital Tract5th edition. New York: Springer; 2004: 421-466.[11] Umashankar T, Patted S, Handigund RS. Endometrial osseousmetaplasia: clinicopathological study of a case and literature review.J Hum Reprod Sci 2010; 3:102-104 authOr(s):1. Dr. Manisha Makkar2. Dr. Pinki Pandey3. Dr. Chinki Gupta4. Dr. Kalyani Kapur naMe OF dePartMent(s)/institutiOn(s) tO WhiChthe WOrk is attriButed:Department of Pathology, M.M institute of Medical Sciences andResearch. Mullana-133207; Ambala, Haryana, India.naMe, address, telePhOne, e-Mail id OF theCOrresPOndinG authOr:Dr. Manisha MakkarSector 4, House no.231Panchkula-134112, Haryana (India)E-mail [email protected]. No. 09501588899 deClaratiOn On COMPetinG interests:No competing Interests. Date of Submission: 25 Jan 2011Date of Peer Review: 12 apr 2011Date of Acceptance: 18 apr 2011Date of Publishing: 13 Jun 2011