SPECT/CT of metastatic struma ovarii.

A 41-year-old woman presented with multiple right lower quadrant masses which were removed and consistent with metastatic follicular thyroid cancer. Thyroidectomy revealed no primary malignancy and evaluation of her ovaries was positive for struma ovarii. The patient was diagnosed with metastatic struma ovarii stage IV. Nine days following the patient's second therapy with I for recurrent disease, planar and SPECT/CT imaging demonstrated multiple I avid peritoneal nodules. At least one of them, located along the medial margin of the spleen, would have been difficult to diagnose without hybrid SPECT/CT imaging.