Background Malignant struma ovarii (MSO) is a very rare disease in which thyroid cancer originates from the ovary. Because it is rare for endocrinologists to encounter patients with MSO, endocrinologists may have a limited understanding of the disease. Therefore, we analyzed and introduced its incidence and clinical course in a tertiary hospital in Korea.
Methods We retrospectively investigated the clinical data of 170 patients who underwent surgery for struma ovarii at the Department of Obstetrics and Gynecology of Samsung Medical Center from 1994 to May 2023.
Results Among 170 patients with struma ovarii, 15 (8.8%) were diagnosed with MSO. The median age of patients with MSO was 48 years (range, 30 to 74), and the median tumor size was 3.3 cm (range, 0.5 to 11.0). Papillary thyroid carcinoma (46.7%) was the most common subtypes followed by follicular thyroid carcinoma (26.7%). All patients were diagnosed after surgery, with no predictions from preoperative imaging. The surgical extent of gynecological surgery was variable. Four patients (26.7%) underwent thyroidectomy for thyroid cancer, while one underwent total thyroidectomy and radioactive iodine therapy for MSO with peritoneal metastasis. Except for one patient who underwent hemithyroidectomy, thyroid stimulating hormone suppression therapy was performed in four patients. Only 53% of MSO patients were consulted by an endocrinologist. With a median follow-up period of 33 months (range, 4 to 156), 11 patients remained disease-free, one experienced progression with peritoneal seeding, and the remaining one was in treatment. There have been no recurrences or deaths due to MSO.
Conclusion An endocrinologist should be involved in establishing a therapeutic plan for MSO, for which the overall prognosis is generally favorable.
Citations
Citations to this article as recorded by
Struma ovarii—diagnostic and treatment strategy: a case report Mohammed Alnaggar, Mueataz A. Mahyoub, Nabil Alshargabi, Li Gong Journal of Medical Case Reports.2025;[Epub] CrossRef
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Struma ovarii is a rare monodermal variant of ovarian teratoma accounting for only 2% of all mature teratomas. To be classified as a struma ovarii, teratoma must be composed predominantly of mature thyroid tissue (> 50%). This tumor is generally benign, although malignant transformation has been reported. Struma ovarii occur mostly as unilateral cases, so bilateral cases are quite rare (less than 6% of cases). Struma ovarii occur largely without symptoms or are accompanied by non-specific symptoms, such as abdominal pain, a palpable abdominal mass, and abdominal distension. The preoperative diagnosis is generally difficult. The incidence of hyperthyroidism has been reported to be 5-10% of patients with struma ovarii. Thus, cases of functional bilateral struma ovarii are very rare. We report a case of bilateral struma ovarii with subclinical thyrotoxicosis and a diffuse goiter, mimicking a malignant ovarian tumor, and include a brief review of related literature.
Citations
Citations to this article as recorded by
Benign Teratoma of the Thyroid Gland Chan Young Oak, Hee Kyung Kim, Tae Mi Yoon, Sang Chul Lim, Hyun Bum Park, Hyung Chul Park, Min Gui Han, Ho-Cheol Kang Endocrinology and Metabolism.2013; 28(2): 144. CrossRef
Metastatic follicular struma ovarii complicating pregnancy: a case report and review of the literature Woohyung Lee, Nam-Joon Yi, Hyeyoung Kim, Youngrok Choi, Minsu Park, Geun Hong, June Young Choi, Hyun Hoon Chung, Kwang-Woong Lee, Do-Joon Park, Hye Sook Min, June-key Chung, Kyung-Suk Suh Korean Journal of Hepato-Biliary-Pancreatic Surgery.2012; 16(3): 123. CrossRef