Endocrine Abstracts

Introduction: Struma ovarii (SO) is a rare ovarian tumor that occurs as part of a teratoma or is found in serous or mucinous cystadenomas and consist of more than 50% thyroid tissue. More uncommon is to diagnose thyroid cancer in struma ovarii and thyroid gland of two different origins. We present a case of follicular thyroid carcinoma arising in struma ovarii of the right ovary and papillary thyroid gland carcinoma.

Case: A 70-year-old woman admitted to gynecology department with abnormal vaginal bleeding. Endometrial biopsy revealed endometrioid adenocarcinoma (G3). Abdominal computed tomography (CT) showed 10.3×7.6 cm cystic tumor arising from the right ovary. Also, multiple uterine myomas and 2.1×2.0 cm left adrenal adenoma were observed in the CT. Total hysterectomy and bilateral salpingo-oophorectomy with pelvic-aortic lymphadenectomy were performed. The histological examination reported vascular invasive with the restricted cellular growth within the capsule follicular thyroid carcinoma of the right ovary and confirmed endometrioid adenocarcinoma (G3) of the uterus body. External pelvic radiotherapy was used postoperatively, but systemic chemotherapy for uterus adenocarcinoma was not prescribed because of co-morbidities. Thyroid ultrasound showed multi-nodular goiter and thyroglobulin level was normal – 19.3 μg/l (0 – 50). Considering the possibility of synchronous tumor of thyroid gland patient underwent total thyroidectomy. Histopathological examination revealed papillary thyroid carcinoma in 3 mm and 5 mm size masses and on immunohistochemistry positive expression of CK - 19. A radiation oncologist decided not to administer radioiodine therapy as an adjuvant treatment because of a minor risk for recurrence. Adrenal adenoma was evaluated by the incidentaloma algorithm and no hormonal activity was detected. In her medical history, she had acoustic neurinoma operation and postoperatively uses small doses of bromocriptine because of hyperprolactinemia. Genetic analysis was performed but neurofibromatosis type 2 diagnosis and other genetical disorders were not approved. No further treatment was deemed necessary at this time and the patient was scheduled for follow-up.

Conclusion: There is no consensus about SO diagnosis and management in the literature because of its rarity, representing only 1% of all ovarian tumors. Therefore, it is important to remember that some of SO are associated with thyroid-type carcinoma and this may significantly alter patient management. Thyroglobulin measurement could be used as one of the follow - up markers evaluating the recurrence. Recurrences may be detected using iodine - 123 scanning, and repeat radioiodine ablation can lead to higher rates of survival.