Metastatic renal cell carcinoma with partial response to sunitinib complicated by ureteral obstruction from necrotic tumor.

The development of molecular therapeutic agents has revolutionized the treatment of metastatic renal cell carcinoma, but the long-term complications of these novel medications are not yet well-defined. We report the case of a 61-year-old woman who presented with metastatic renal cell carcinoma to the liver and contralateral kidney and renal pelvis 6 years after nephrectomy. Treatment with four cycles of sunitinib malate resulted in an initial near-complete radiographic response. Subsequently, the patient presented with flank pain, acute renal failure, and hydronephrosis of her solitary kidney during her fourth cycle of treatment. A temporizing percutaneous nephrostomy tube was placed, and antegrade contrast studies showed a filling defect and complete distal ureteral occlusion. Ureteroscopy revealed ureteral obstruction by a soft-tissue mass. Pathologic examination demonstrated necrotic renal cell carcinoma, presumably due to sloughing of the previously identified renal pelvic metastasis. We discuss the implications of this unusual complication of complete ureteral obstruction from necrotic tumor in a patient with a near-complete response to sunitinib.