Functional Imaging in 2 Rare Cases of Struma Ovarii With Contrasting Features.

Area of Science:

• Nuclear Medicine
• Oncology
• Gynecologic Pathology

Background:

• Struma ovarii, a rare germ cell tumor, is composed of thyroid tissue.
• It can present as benign or malignant, with varying clinical and imaging features.
• Diagnosis and management can be challenging due to its rarity.

Purpose of the Study:

• To present two distinct cases of struma ovarii, one benign and one malignant.
• To illustrate the utility of functional imaging in the diagnosis and management of struma ovarii.
• To highlight rare presentations, including coexisting Graves' disease and peritoneal metastases.

Main Methods:

• Case report presentation of two patients with struma ovarii.
• Preoperative diagnosis using Technetium-99m (Tc-99m) and Iodine-131 (I-131) scans for benign struma ovarii.
• Postoperative diagnosis and assessment of peritoneal metastases using 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F-FDG PET/CT) and post-radioiodine therapy scans for malignant struma ovarii.

Main Results:

• Benign struma ovarii diagnosed preoperatively with Tc-99m and I-131 scans, coexisting with Graves' disease.
• Malignant struma ovarii with peritoneal metastases detected postoperatively via 18F-FDG PET/CT and post-I-131 therapy scans.
• Functional imaging successfully identified disease extent and response to therapy in both cases.

Conclusions:

• Struma ovarii, though rare, can exhibit diverse presentations requiring comprehensive diagnostic workup.
• Functional imaging modalities like radioiodine scans and 18F-FDG PET/CT are essential for accurate diagnosis and monitoring.
• Radioiodine therapy may be a treatment option for malignant struma ovarii with metastatic disease.