Follicular variant of papillary thyroid carcinoma arising from a dermoid cyst: a rare malignancy in young women and review of the literature.

OBJECTIVE: Benign or mature cystic teratomas, also known as dermoid cysts, are composed of mature tissues, which can contain elements of all three germ cell layers. Malignant transformation of a mature cystic teratoma is more common in postmenopausal women, however, it can also, rarely, be identified in younger women. We present a case of a 19-year-old woman with malignant transformation of an ovarian mature cystic teratoma. CASE REPORT: Our case was a 19-year-old woman, who was diagnosed postoperatively with follicular variant of papillary thyroid carcinoma in a mature cystic teratoma. She underwent right cystectomy for adnexal mass. Postoperative metastatic workup revealed a non-metastatic disease and the patient did not undergo any further treatment. After 2 months, a near-total thyroidectomy was performed. Serum thyroglobulin levels were monitored on follow-up and the patient is asymptomatic.
CONCLUSION: Malignant transformation of a dermoid cyst is a rare ovarian neoplasm. We believe that unilateral oophorectomy or cystectomy is a reasonable treatment option for cases in which there is no evidence of capsular invasion, vascular invasion or gross metastasis, and preservation of fertility is desired. Total thyroidectomy was diagnosed in selected cases. Serial serum thyroglobulin should be used as a tumor marker for follow-up.