Malignant Struma Ovarii in Refractory Graves Disease: A Case Report

ABSTRACT Objective: Described is a rare and complex case of malignant struma ovarii containing papillary thyroid carcinoma in the setting of refractory Graves disease. We discuss the decision-making challenges of this case regarding both short- and long-term clinical management in absence of clear guidelines on the topic. Methods: A retrospective review of the patient's clinical, radiologic, and pathologic data and a review of literature. Results: A 42-year-old African American woman with hypertension and Graves disease presented with persistent dysmenorrhea and a right ovarian cyst. The patient underwent total laparoscopic hysterectomy, salpingectomy, and right oophorectomy, revealing malignant struma ovarii of the right ovary with a focus of papillary thyroid carcinoma. Graves disease and struma ovarii were treated concurrently with pre-operative methimazole suppression, total thyroidectomy, diagnostic and therapeutic 123I and 131I scans, respectively, diagnostic laparoscopy for retroperitoneal and intra-abdominal lymphadenopathy assessment, and completion left oophorectomy. Postoperatively, thyroid function tests had normalized, and the serum thyroglobulin level was undetectable. Conclusion: Described is a rare case of malignant struma ovarii containing papillary thyroid carcinoma, incidentally discovered during the surgical management of dysmenorrhea, in the setting of refractory Graves disease. Malignant struma ovarii and Graves disease are very rarely comorbid, and the presence of both diseases complicates the diagnosis and management of each individual disease entity. No consensus exists on appropriate management of comorbid malignant struma ovarii and Graves disease. Abbreviations: FT4 = free thyroxine;MSO = malignant struma ovarii;PTC = papillary thyroid carcinoma;RAI = radioactive iodine ablation;SO = struma ovarii;TSH = thyroid-stimulating hormone