Struma Ovarii: Clinical, Radiological, and Histopathological Insights: A Retrospective Cohort Study

Objective: Struma ovarii (SO) is a rare ovarian tumor, primarily arising from ovarian dermoid cysts that contain thyroid parenchyma. Due to the rarity of cases, we aimed to present clinical factors, management strategies, and outcomes related to SO patients. Methods: This is a retrospective descriptive cohort study of SO patients from 2010 to 2023 in a tertiary referral center. Data were extracted from the local electronic records, and variables were analyzed. Pathology slides and radiological images were re-evaluated by an expert pathologist and radiologist. Results: The study included 12 cases of SO, with a median age of 47.92 years (SD: 13.55). The average lesion size in imaging was 12.1 cm (range 7–37.5 cm). Ten patients presented with unilateral tumors (83.3%) and two presented with bilateral tumors (16.7%). Mild ascites was present in two cases (16.7%) while moderate ascites was present in one case (8.3%), who had also presented with marked left pleural effusion. Salpingo-oophorectomy was performed in six patients (50%), while the other six patients underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy. The thyroid tissue of the SO was benign in 10 cases (83.3%) and malignant in 2 cases (16.7%), including 1 case of highly differentiated follicular carcinoma and 1 case of papillary thyroid carcinoma. Univariate and multivariate logistic regression analyses showed no statistically significant associations for predictors of malignancy. Univariate and multivariate logistic regression analyses showed no statistically significant associations for predictors of malignancy. Conclusion: SO is a very rare ovarian tumor with no characteristic clinical or imaging findings. Follow-up is necessary to demonstrate the prognosis of both benign and malignant SO.