Malignant struma ovarii found in a teratoma of an undescended ovary: A case report

Abstract

Teratomas are the most common neoplasm of the ovary but transformation of a teratoma is very rare. Furthermore, transformation to papillary thyroid carcinoma is even more uncommon. Mullerian anomalies and undescended/maldescended ovaries are also rare congenital conditions that have a low estimated prevalence. We present an extremely rare case of a 33-year-old female presenting with a struma ovarii with malignant transformation to papillary thyroid carcinoma within a teratoma arising from an undescended ovary and fallopian tube with a concomitant Mullerian anomaly. While there are several cases of similar pathologies reported separately, there has not been a similar case to our patient. Undescended ovary and fallopian tube, unicornate uterus, stuma ovarii, and malignant transformation of a struma ovarii and mature teratoma are all extremely rare conditions that have not been reported to co-occur within a single patient in the current literature.