Malignant struma ovarii. A case report and review of the literature.

Malignant struma ovarii is a rare form of ovarian carcinoma; only 3 cases of its pure papillary type have been reported in the literature. A new case of malignant papillary struma ovarii arising in an asymptomatic 32-year-old woman is presented. Due to its rarity, there has been confusion in the diagnosis and management of malignant struma ovarii. Criteria for the diagnosis of malignant papillary struma ovarii are proposed. Conservative treatment after a complete staging procedure is possible due to the usually benign course and low incidence of metastases of this tumor.