Papillary carcinoma within struma ovarii: A case report with literature review

Struma ovarii is an ovarian teratoma in which thyroid tissue predominates. The reported incidence ranges between 2% and 10% of all cases of teratoma. Malignant transformation, in the form of papillary or follicular carcinoma, is an even rarer event. We report a case of papillary cancer within a stru ma ovarii and review the pertinent literature. A 3-cm focus of malignancy w as discovered after excision of a rapidly progressing pelvic mass in a 35-y ear-old woman with a family history of dermoid cysts. She was treated with unilateral salpingo oophorectomy, thyroidectomy, and 100 mCi of iodine-131 to ablate residual thyroid tissue and potential microscopic metastasis. Aft er these procedures, the whole body scan revealed no uptake in the abdomina l or pelvic region. A review of the literature since 1970 revealed less tha n 25 cases of malignancy of the papillary type within struma ovarii and a g reater rate for follicular carcinoma. The treatments ranged from exclusive local excision to extensive surgery, with additional thyroidectomy, radioio dine, and even chemotherapy in selected cases. Malignant struma ovarii can be managed satisfactorily by combining surgical procedures with treatment o ptions commonly used for primary thyroid carcinoma. The outcome for papilla ry carcinoma is overall favorable, even if a less aggressive therapeutic ap proach is chosen. Follicular neoplasia. has a higher rate of recurrence and a worse prognosis.