Primary carcinoid tumor arising in a mature cystic teratoma of the ovary: a case report.

OBJECTIVE: To present an extremely rare case of a primary carcinoid tumor arising in a mature cystic teratoma of the ovary. Malignant transformation of mature cystic teratoma is an uncommon complication occuring in approximately 1-3% of patients with mature cystic teratoma. CLINICAL PRESENTATION AND INTERVENTION: A 54-year-old woman presented with abdominal swelling and abnormal uterine bleeding. Physical examination revealed a smooth, non-painful, 8-9 cm diameter mass in the right anterior pelvis which was diagnosed histologically as carcinoid tumor arising in a mature cystic teratoma. The patient underwent a total abdominal hysterectomy with bilateral salpingo-oophorectomy and was scheduled for surveillance CT of the abdomen and pelvis at 3-monthly intervals. CONCLUSION: This case adds to the rare reports in the literature of a carcinoid of low malignant potential occurring in a mature cystic teratoma. The treatment for early-stage ovarian carcinoid tumors confined to one ovary is surgery alone and excellent outcomes can be expected in these cases.