Malignant struma ovarii- Report of a rare case

Struma ovarii is a highly specialized form of mature ovarian teratoma in which the ovary contains >50% of thyroid tissue. It accounts for 1 – 3% of benign teratomas of the ovary. Malignant transformation is observed in 5-37% cases of struma ovarii. Peak age of incidence 4 - 5th decade with excellent prognosis. We report a rare form of malignant struma ovarii, composed of a follicular variant of papillary thyroid carcinoma with capsular invasion. A65-year-old hypertensive postmenopausal female presented with complaints of pain in abdomen, pelvic mass, frequent micturition, since 3 days. A pelvic sonogram showed an enlarged heterogenous right ovarian mass of sized 12 x 9 x 5 cm, with solid cystic lesion. Left ovary was unilocular and cystic of sized 5.5 x 4 x 3 cm. The uterus and cervix appeared to be normal. She underwent an exploratory laparotomy, and a total abdominal hysterectomy with bilateral salpingo-oophorectomy. Based on histopathological and radiological features an impression of follicular variant of papillary carcinoma of thyroid with capsular invasion was favoured. : The patient was successfully treated with total abdominal hysterectomy with bilateral salpingo-oopherectomy. There are no sign of recurrence and metastasis two months after surgery. Patient is under regular follow up. : Malignant struma ovarii is a medical rarity and very few studies have been reported.