Malignant Struma Ovarii: A Distinctive and Rare Variant of Ovarian Tumors

Struma ovarii is a very rare histological entity among ovarian tumors. We report the case of a 35-year-old woman presenting with pelvic pain associated with dysmenorrhea. Radiologic examination revealed a left ovarian mass with no signs of metastasis. The patient underwent surgical treatment, which confirmed the presence of thyroid tissue in the left ovary, suggestive of invasive follicular carcinoma. The aim of this case is to highlight this exceptional histological type, which first requires an appropriate diagnostic strategy to rule out metastatic involvement from a primary thyroid tumor before confirming the diagnosis of struma ovarii.