Delayed disseminated intraperitoneal mature cystic teratoma following prior dermoid cyst rupture: a case report

Introduction and importance: Mature cystic teratoma (MCT) is the most common benign ovarian germ cell neoplasm. Rupture is uncommon and may, rarely, lead to delayed intraperitoneal dissemination mimicking advanced ovarian cancer. This case is notable for the 22-year interval between surgery for a ruptured dermoid cyst and presentation with extensive disease resembling peritoneal carcinomatosis. Case presentation: A 46-year-old premenopausal woman with a history of left salpingo-oophorectomy for a ruptured dermoid cyst in 2004 presented with abdominal pain, distension, and a palpable mass. Magnetic resonance imaging revealed a 6–7 cm complex right adnexal mass and multiple peritoneal, omental, and mesenteric lesions measuring up to 3–4 cm. CA-125 (cancer antigen 125) (61 U/mL) and CA19-9 (carbohydrate antigen 19-9) (56 U/mL) were mildly elevated, whereas alpha-fetoprotein, beta-human chorionic gonadotropin, carcinoembryonic antigen, and lactate dehydrogenase were normal. Total abdominal hysterectomy, right salpingo-oophorectomy, omentectomy, appendectomy, and excision of all visible implants achieved no macroscopic residual disease. Frozen section and final histopathology showed mature teratomatous tissue without immature or malignant elements. Clinical discussion: The findings were most consistent with disseminated mature teratomatous implants, most likely associated with the previous rupture, although occult residual implants or a contralateral MCT could not be excluded. The main differential diagnoses were malignancy, growing teratoma syndrome, and gliomatosis peritonei. Conclusion: In women with a prior MCT rupture, multifocal fat-containing peritoneal lesions should raise suspicion for disseminated mature teratoma. In this patient, complete macroscopic excision was associated with a favorable short-term outcome; longer follow-up is required.