Abstract
BACKGROUND: Mature cystic teratomas (MCT) of the ovary are benign ovarian germ cell neoplasms. Malignant transformation is possible but rare and ovarian carcinoid tumors in MCT are among the most extremely rare subtypes. CASE PRESENTATION: We report a case of a 60-year-old Iranian woman suffering from postmenopausal bleeding and hypogastric pain for the last 40 days. An adnexal mass was detected during the physical examination. Ultrasound imaging showed a (55 × 58) mm mass in the left ovary. Total abdominal hysterectomy, bilateral salpingooophorectomy and comprehensive staging surgery were performed for the patient. Intraoperative frozen section of the left ovarian mass was indicative of a malignant tumor. She was diagnosed with a carcinoid tumor with benign mucinous cystadenoma arising on MCT of the ovary, confirmed in the histopathology and immunohistochemistry examination. The tumor was classified as low grade and no chemotherapy cycles were considered. The patient was followed up long-term and no recurrence was observed during 14 months of examinations. CONCLUSION: Ovarian carcinoids arising from MCT are rare neuroendocrine neoplasms, and proper diagnosis of these tumors requires careful histopathology evaluation and appropriate examination. Therefore, it is necessary to consider these tumors as a possible differential diagnosis and evaluate them in individuals (especially postmenopausal women) who have abdominal pain or abnormal bleeding and a palpable mass.