Unusual Case of Malignant Struma Ovarii and Cervical Thyroid Cancer Preceded by Ovarian Teratoma: Case Report and Review of the Literature

Abstract

Objective. To present a rare case of malignant struma ovarii (MSO) and synchronous thyroid cancer, review the medical literature, and present the latest trends in management. Methods. The case of a woman with MSO and concomitant thyroid cancer is presented, including clinical presentation, treatment, and follow-up care. A search of the English-language literature was conducted using MEDLINE and Google Scholar data bases. Results. We found 10 publications (one abstract) describing 10 patients with MSO and concomitant thyroid cancer. Six additional patients were reported by a study that analyzed the SEER (cancer registry) database. The median age of women was 42 years, with the majority of them presenting with abdominal symptoms. Histologically, most tumors were papillary carcinomas in both organs. In 5 patients, there was extrathyroidal tumor extension at time of surgery. Conclusion. MSO can occasionally coexist with highly aggressive eutopic thyroid cancer. Although this concurrence is even rarer than MSO, clinicians should routinely investigate for possible synchronous thyroid cancer in all cases of MSO and also consider aggressive postoperative treatment including thyroidectomy and radioiodine ablation therapy in cases of MSO.

Malignant Thyroid-type Papillary Neoplasm in Struma Ovarii: A Case Report

“…Teratoma is a subtype of germ cell tumor that arises from one or more of the three germ cell layers. They can present as benign cystic lesions to overt malignancies [4]. Malignant counterparts of teratomas are termed immature teratomas.…”

“…SO is a monodermal ovarian teratoma, whose architecture is composed of more than 50% of thyroid tissue [3,6]. It contributes to approximately 2-3% of all ovarian tumors and 2-5% of all ovarian teratomas [1][2][3][4]. The incidence of SO is higher in older adults, although it has also been reported in younger women [7].…”

“…However, it may also produce non-specific symptoms of a pelvic mass such as abdominal pain, bloating, or abnormal menstrual cycles [6][7][8]. The majority of SO cases are benign, with only 5-10% cases being malignant [4]. Therefore, a malignancy arising in a SO is a rare event [4].…”

“…The majority of SO cases are benign, with only 5-10% cases being malignant [4]. Therefore, a malignancy arising in a SO is a rare event [4]. The average age of females at the diagnosis of MSO is 43 years [2].…”

“…Malignant struma ovarii (MSO) are usually asymptomatic. However, thyrotoxicosis is reported to be present in 5-8% of the affected patients [4]. Our case discussion pertains to the rare variant of MSO harboring a focus of the classical or conventional type of PTC.…”