Follicular Variant of Papillary Thyroid Cancer Located in Malignant Struma Ovarii with Pulmonary Metastasis: A Case Report

Abstract

The phenomenon of malignant transformation in struma ovarii is exceedingly rare. Malignant struma ovarii is usually asymptomatic and infrequently diagnosed preoperatively. Because of its rarity, there is no consensus about diagnosis and management in the literature. We here present a case of a 67-year-old female diagnosed with malignant struma ovarii with pulmonary metastasis. She presented with the complaint of abdominal pain and distension for the last 6 months. On imaging, a large complex cystic mass lesion was seen arising from the pelvis containing solid component and having papillary projections from the wall. Total abdominal hysterectomy with bilateral salpingo-oophorectomy with an appendectomy, omentectomy, bilateral pelvic lymphadenectomy, ileal resection, anastomosis, descending colonic resection and colorectal anastomosis was done. Postoperative histopathology confirmed malignant struma ovarii of the left ovary with a predominantly follicular pattern. CT chest showed multiple nodules suggestive of pulmonary secondaries. These lesions showed tracer uptake on 1^31I—whole-body scan. Total thyroidectomy was also performed as second-stage procedure. Patient underwent high-dose radioiodine ablation therapy.