Struma Ovarii with Papillary Thyroid Carcinoma and Metastasis to the Appendix: A Case Report and Literature Review.

Struma ovarii is an infrequent type of teratoma arising from the ovary accounting for only 2% of all ovarian teratomas. These tumors have a benign biology with rare malignant transformation in about 3% of cases. The most common malignant transformation that arises from struma ovarii is papillary thyroid carcinoma.