Yolk sac tumor of the ovary with synchronous ipsilateral and contralateral benign cystic teratoma

Yolk sac tumor and teratoma are germ cell tumors, the former showing preferential differentiation toward yolk sac structures, while teratoma consists of tissues that originate from at least two embryonic germinal layers. The yolk sac tumor is characterized by significantly elevated serum alpha fetoprotein level.The aim of this study was to present a rare case of yolk sac tumor of the ovary in a young female with synchronous ipsilateral and contralateral mature cystic teratoma.A Caucasian 19-year-old female presented with severe abdominal pain and abdominal swelling. Ultrasound examination revealed a large, 15 cm in diameter tumor of the right ovary with suspicion for adnexal torquation and tumor rupture. Immediate surgery was performed and right uterine adnexa was removed. The pathologic examination showed predominantly solid ovarian tumor. A few centimeters in diameter cysts were also evident, filled with sebum, keratin debris and hair. Microscopic examination revealed tumor composed of meshwork of anastomosing spaces and cysts lined by a single layer of tumor cells. Schiller–Duval bodies were also present. Postoperative ultrasound follow-up one week after the initial surgery confirmed the intraoperative suspicion of ovarian tumor in the contralateral ovary. The left ovarian tumor was resected and histopathology revealed a mature cystic teratoma measuring 5 centimeters in maximal diameter.Benign teratoma can appear synchronously or metachronously with yolk sac tumors in the ipsilateral or contralateral ovary. Recognition of the benign nature of the teratomatous component is important to avoid misinterpretation of mixed germ cell tumor and possible overtreatment of these patients.