{"paper_id":"649649ea-693b-4499-a107-565cdccc5082","body_text":"Case Report  | JOGCR. 2026;11(9): 894-896 \n     Volume 11, September 2026      Journal of Obstetrics, Gynecology and Cancer Research \nJournal of Obstetrics, Gynecology and Cancer Research | ISSN: 2476-5848 \n \n \nEndometriosis Stones in Ovary: A Case Report \n \nMaral Hosseinzadeh* , Parisa Taherzadeh, Mitra Nemati  \n \nDepartment of Obstetrics and Gynecology, Shahid Beheshti University of Medical Sciences, Tehran, Iran \nArticle Info  ABSTRACT \n  \n   10.24200/jogcr.11.9.894 \n \n \n \nBone formation within ovarian lesions, such as endometriotic cysts and \ncystadenocarcinoma, is a rare clinical finding. This report documents the case of a \n42-year-old woman presenting with chronic lower abdominal pain and a palpable left \nadnexal mass. Init ial blood work was unremarkable; however, transvaginal \nultrasonography identified a complex 29 mm × 32 mm cystic lesion containing solid \ncomponents, leading to initial concerns regarding potential ovarian malignancy. The \npatient underwent an elective oopho rectomy. Surgical exploration revealed an \nenlarged, pale ovary characterized by foci of endometriosis and the presence of two \ndistinct stone -like fragments. Histological analysis subsequently confirmed the \ndiagnosis of an endometrioma. Although the exact p athogenesis of ovarian \nossification remains poorly understood and requires further investigation, this case \nhighlights the necessity of surgical intervention for such masses. Importantly, \nclinicians should remain aware that despite the concerning appearanc e of ossified \nadnexal structures, they may ultimately prove to be benign entities. \nKeywords: Endometriosis, Stone, Case report, Adnexal tumor \n \nReceived: 2025/01/05 \nAccepted: 2025/04/26 \nPublished Online: 18 Jul. 2026 \n \n \n \n \n \n \n \n \nCorresponding Information:  \nMaral Hosseinzadeh, \nDepartment of Obstetrics and Gynecology, \nShahid Beheshti University of Medical \nSciences, Tehran, Iran \n \nEmail: maral.hosseinzadeh65@gmail.com \n \n \n \nCopyright © 2026, This is an original open-access article distributed under the terms of the Creative Commons Attribution-noncommercial \n4.0 International License which permits copy and redistribution of the material just in noncommercial usages with proper citation . \n \n1. Introduction\nBone formation and calcifications in the ovaries are \ntypically associated with mature teratomas and are \nrarely observed in other circumstances (1). Several \nuncommon causes of bone formation and calcification \nin the ovary have been reported, including \nendometriotic cysts, cystadenocarcinoma, primary or \nmetastatic carcinoma, fibromas, and leiomyomas; \nhowever, these have been described only in a few \ncases. This condition has been associated with some \ncases of infertility, but it remains uncommon (2).   \nThere have also been reports of bone formation in the \novary without any apparent cause. This may result from \nheterotopia or metaplasia of the ovarian connective \ntissue (3,4). Only a few cases of ovarian bone \nformation secondary to endometriosis have been \nreported in the medical literature (5). In this case report, \nwe describe a woman with significant ossification and \ncalcification of the ovarian stroma associated with \nsmall areas of endometriosis in her ovary. \n \n2. Case Presentation \nA 42 -year-old Iranian woman (gravida 3, para 3) \npresented to the gynecology clinic with a 1‑month \nhistory of lower abdominal pain. The pain was colicky \nand was not associated with fever, abdominal \ndiscomfort, nausea, or vomiting. She denied a history \nof weight loss, difficulty with micturition, heavy \nmenstrual bleeding, anorexia, dyspnea, or dyspareunia. \nShe had a regular menstrual history with normal \nmenstrual flow. No significant personal or famil y \nhistory was reported. \nOn initial physical examination, she had normal vital \nsigns. A tender mass on the left side of the adnexa was \ndetected during abdominal palpation, with no other \nabnormal findings. Pregnancy was excluded. Blood \nexamination results, including complete blood count, \nC-reactive protein, hormone profile, and tumor \nmarkers, were all within reference ranges. Laboratory \nanalysis showed that Cancer Antigen 125 (CA -125), \nCancer Antigen 19 -9 (CA 19 -9), Carcinoembryonic \nAntigen (CEA), the hormone profile, and C -reactive \nprotein were within normal limits.   \nTransvaginal ultrasonography revealed a complex \ncystic lesion measuring 29 mm×32 mm with solid \ncomponents in the left ovary, raising concern for \nmalignant ovarian cancer. Magnetic resonance imaging \nof the abdomen and pelvis revealed a midline pelvic \nmass measuring 37×24 mm in the left ovary with thick \nseptations. It contained nonhomogeneous solid \ncomponents and an extensively calcified shell. \n\n\n895 Endometriosis Stones in Ovary \n      Volume 11, September 2026      Journal of Obstetrics, Gynecology and Cancer Research \nThe patient was scheduled for elective \noophorectomy. During surgical exploration, an \nenlarged, ovoid, pale ovary with foci of endometriosis \nwas identified (Figure 1). The left ovary was carefully \ndissected to preserve tubal integrity. On bisection, the \novary revealed soft, dark brown material with \nextensive calcification. Two well -defined, stony \nfragments of dense tissue were noted within the \nendometrioma.   \nSurgical pathological examination of the specimen \nshowed the presence of an ovarian cyst and a portion \nof the fallopian tube. The ovarian cyst measured 4 cm \nin diameter and was associated with a segment of the \nfallopian tube measuring 3 cm in length. The thickness \nof the cyst wall ranged from 3 mm to 8 mm. Two stone \nfragments measuring 6 mm×5 mm×2 mm and 5 mm×4 \nmm×2 mm were identified. Histologically, the lesion \nwas consistent with an endometrioma. Endometrial \nglands and stroma were present throughout the c yst \nwall, and hemosiderin deposits were noted.   \nImmunohistochemical studies were negative for \ncytokeratins, CA -125, and WT1. There was no \nevidence of malignant transformation in the tissue, and \nall findings suggested a benign lesion. The patient was \ndischarged a few days after surgery without \ncomplications. At the 6‑month follow‑up, she reported \ncomplete resolution of symptoms. \n \n \n \n     Figure 1. Enlarged, ovoid, pale ovary with foci of \nendometriosis \n \n3. Discussion \nIn this article, we report a case of an ovarian cyst that \nunderwent calcification and ossification in the presence \nof endometriosis. Endometriosis is a condition \ncharacterized by the presence of endometrial tissue \noutside the uterus, leading to various sym ptoms, \nincluding pain. In this case, the ovarian cyst had \nbecome firm and calcified within the surrounding \ntissue. This finding may have important implications \nfor the management and treatment of the cyst.   \nIt is important to note that calcified adnexal masses \nmay raise suspicion for ovarian tumors and often \nrequire surgical intervention. In cases where imaging \nstudies suggest malignancy but blood tumor markers \nare normal, immunohistochemical studies can help  \ndifferentiate between benign and malignant lesions. \nImmunohistochemistry involves the use of specific \nantibodies to detect particular proteins in tissue \nsamples. This technique can help identify markers \nassociated with malignant tumors, such as cytokeratins, \nCA-125, and WT1. However, it is important to note \nthat the absence of these markers does not necessarily \nexclude the possibility of malignancy. \nConservative management may be considered in \ncases of focal calcification in otherwise \nultrasonographically normal ovaries. However, \nsurgical intervention remains the treatment of choice \nfor adnexal masses with extensive calcification. In our \npatient, surgical intervention was chosen because of \nrecurrent episodes of abdominal pain. Nevertheless, the \nlikely benign nature of an extensively calcified adnexal \nmass should be considered when planning surgical \nmanagement.   \nHeterotopic bone, or the presence of bone tissue in \nabnormal locations such as the ovary, has been linked \nto extensive endometriosis. Researchers have \nsuggested that osseous metaplasia the transformation \nof one type of tissue into bone may occur as a response \nto the ongoing inflammatory damage caused by \nendometriosis.   \nCampo et al., provided additional evidence \nsupporting the inflammatory theory by reporting a case \nof osseous metaplasia in a patient with an Intrauterine \nDevice (IUD) present in both the uterus and the \novaries. Several reported cases of ossification have also \noccurred in association with ovarian neoplasms, \nincluding luteinized thecomas, Sertoli -Leydig tumors, \nmucinous cystadenomas, and fibromas. These \nneoplasms have been found to contain calcified \nstructures described as bony or bone‑like in \nappearance. In ovarian neoplasms, ossification may be \nrelated to the production of calcified material by tumor \ncells or to the presence of bone‑forming cells within the \ntumor tissue. In addition to these cases, ossification has \nalso been reported without any associated \nabnormalities. Rosa e Silva et al., and Shipton et al., \nboth published studies describing this phenomenon in \ndetail. \n \n4. Conclusion \nOssification in the ovary is rare, and its pathogenesis \nremains unclear. Surgical intervention remains the \nprimary treatment for ossified adnexal masses; \nhowever, the likely benign nature of such masses \nshould be carefully considered. Further research is \n\n\nMaral Hosseinzadeh, et al. 896 \nVolume 11, September 2026      Journal of Obstetrics, Gynecology and Cancer Research \nneeded to better understand the pathogenesis of ovarian \nossification and to develop more effective management \nstrategies. \n \n5. Declarations \nAcknowledgments \nThe authors would like to thank the patient and her \nfamily. \n \n \nEthical Considerations \nformed written consent was obtained from the patient \nfor the publication of this case report and any \naccompanying images. The patient’s anonymity was \nstrictly maintained by removing all personal \nidentifiers. \n \nAuthors' Contributions \nP.Taherzadeh :Diagnosis, and writing original draft, \nM. Nemati: Writing, review and editing, \nM.Hosseinzadeh: Supervision. All authors approved \nthe final manuscript and take responsibility for the \nintegrity of the data. \n \nConflict of Interest \nThe authors declare no conflict of interest. \n \nFund or Financial Support \nThe authors declared no fund.\n \n1. Zahn CM, Kendall BS. Heterotopic bone in the \novary associated with a mucinous cystadenoma. \nMil Med. 2001;166(10):915 -7. \n[doi:10.1093/milmed/166.10.915] \n2. Kramer HMC, Rhemrev  JPT. Secondary \ninfertility caused by the retention of fetal bones \nafter an abortion: a case report. J Med Case Rep. \n2008;:208. [doi:10.1186/1752-1947-2-208] \n3. Eva A, Shipton S, Devenish Meares. \nHeterotopic bone formation in the ovary. \n1965;5(2):100-2. [ doi:10.1111/j.1479-\n828X.1965.tb00298.x] \n4. Ding DC, Yu MH, Liu JY. Autocalcification of \nthe ovary. Int J Gynaecol Obstet. \n2002;79(2):161-2. [ doi:10.1016/S0020-\n7292(02)00229-1] \n5. Shaco-Levy R, Lazer T, Piura B, Wiznitzer A. \nOvarian ossification associated with \nendometriosis. Clin Exp Obstet Gynecol. \n2007;34(2):113-4. [PMID:17629168]\n \n \n \nReferences \nHow to Cite This Article:  \nHosseinzadeh M, Taherzadeh P, Nemati M. Endometriosis Stones in Ovary: A Case Report J Obstet Gynecol Cancer \nRes. 2026;11(9):894-896. \nDownload citation:                             RIS | EndNote | Mendeley |BibTeX |","source_license":"CC0","license_restricted":false}