ABSTRACT
BACKGROUND: Epithelial ovarian cancer development before menarche is extremely rare. CASE: We report a prepubertal girl who developed ovarian mucinous carcinoma with mural carcinosarcomatous components. SUMMARY AND CONCLUSION: Magnetic resonance imaging showed a polycystic mass with solid components. The left adnexa was removed. Histological analysis revealed a mucinous tumor with mural carcinosarcomatous components. Three weeks later, ascites and peritoneal metastasis were detected. The patient received a combination therapy of paclitaxel with carboplatin. After 4 chemotherapy cycles the right adnexa, uterus, partial omentum, and pelvic peritoneum were removed. Four additional paclitaxel/carboplatin therapy cycles were administered. She remains free from recurrence after 29 months. To our knowledge, this is the first report of ovarian mucinous carcinoma with mural carcinosarcomatous components in a prepubertal girl.