Renal Metastasis From Primary Thyroid Cancer on 131I and MRI Imaging

A 66-year-old woman with a history of papillary thyroid cancer status after total thyroidectomy underwent I radioiodine ablation therapy 3 months after surgery. Posttherapy whole body planar imaging revealed focal intense I uptake in the posterior right abdomen. SPECT/CT of this region localized the uptake to the medial lower pole of the right kidney. Further evaluation with MRI demonstrated a correlative suspicious right renal mass. The patient underwent right partial nephrectomy with pathology demonstrating that the renal mass was of thyroidal origin (papillary subtype).