Uncommon malignancy arising within mature ovarian teratoma: Case report and literature review

Background. Clear cell carcinoma of the ovary developing in the background of an ovarian teratoma represents an extremely rare entity of the gynecologic tract. Giving the rarity of this entity, the histologic challenges, prognosis and the adequate treatment is still uncertain. Methods. We herein present a case of clear cell carcinoma coexisting with a teratoma, accompanied by a scrutinous literature review. The authors have reviewed all case reports published in the literature (1978-2021), adding our new case, in order to enrich current literature data. Results. A thorough search of the PubMed/MEDLINE and Google Scholar databases has revealed 7 cases of clear cell carcinoma of the ovary developing in association with a teratoma. Out of the 7 cases, 4 were part of a more complex tumor, including other malignancies (e.g. angiosarcoma, endometrioid carcinoma). The mean size of the tumors was 16 cm and most patients died of disease or suffered multiple recurrences. Additionally, we report a case of a 54-year-old patient who presented with an ovarian tumor and which upon microscopic examination featured a cystic structure lined by squamous keratinizing epithelium and sebaceous glands. Inside the wall of the cyst, a small nodule made out of tubules and papillae lined by clear cells, which invaded the surrounding stroma was identified. Four months later, the patient developed a small nodule in the liver and she has subsequently received adjuvant chemotherapy. Conclusion. Clear cell carcinoma of the ovary developing in association with a teratoma is an extremely rare entity, that requires thorough sampling of the cyst and which is usually associated with a relatively poor prognosis.