Papillary carcinoma in struma ovarii: A case report.

Abstract

Introduction: Struma ovarii is a form of teratoma composed predominantly of thyroid tissue, comprising 2.7% of all ovarian teratomas. 1 Malignancy may occur in 5-10% of struma ovarii. 2 There is controversy as to the best management and follow-up of these cases. We describe a rare case of a 45-year-old woman with struma ovarii showing features of papillary carcinoma. Case report: The patient presented with 12 months of pelvic pain and heavy irregular vaginal bleeding. A pelvic ultrasound showed a small left-sided dermoid cyst. Laparoscopic salpingo-oophorectomy was performed. Sections of the ovarian cyst showed a mature teratoma. Thyroid tissue comprised approximately 50% of the specimen. The follicular cells displayed nuclear features of papillary carcinoma. This was present both in classical papillary form and as a follicular variant with prominent psammoma bodies. The patient was subsequently investigated to exclude a primary thyroid neoplasm. Thyroid function tests were normal. An ultrasound showed multiple benign thyroid nodules, one of which had minor non-specific uptake on PET scan. Subsequent FNA cytology was benign. Conclusion: This patient had an incidental finding of papillary carcinoma in struma ovarii, independent of any thyroid pathology. This entity has a good prognosis in the absence of extra-ovarian spread.