Unusual Tc-99m MAG3 Uptake in Unknown Bone Metastases

A 55-years-old female patient with a diagnosis of transitional cell carcinoma of the urinary bladder and a tight hydronephrotic kidney(1) was referred for evaluation of renal function. On Tc-99m MAG3 scan, abnormal accumulation of tracer(2) was noted in the region of the right sacroiliac joint with nonvisualization of the right kidney. Subsequent correlation with CT scan and Tc-99m MDP bone scintigraphy confirmed the Tc-99m MAG3 uptake in a metastasis involving the right sacroiliac joint.(3-8)