Laparoscopic excision of malignant struma ovarii and 1 year follow-up without further treatment

Malignant struma ovarii is a very rare, highly specialized form of mature ovarian teratoma, in which thyroid tissue is the predominant element. Because of the nonspecific symptoms and a lack of specific features in imaging studies, preoperative diagnosis is very difficult, and there is no standard treatment. Struma ovarii, which is potentially malignant, should be included in the differential diagnosis of an ovarian mass with cystic, solid, or mixed cystic and solid structure. Standardized treatment of malignant struma ovarii still remains undefined; currently the laparoscopic removal of the tumor may be a treatment option, and thyroidectomy and radiotherapy with 131I should be offered.