Urographic manifestations of metastatic melanoma.

Urinary tract involvement with metastatic malignant melanoma occurs much more commonly than generally thought. It is usually part of a disseminated process with a poor life expectancy. The renal parenchyma is the most common site affected, although this is infrequently detected roentgenographically. Urothelial involvement of the renal pelves, ureters, and bladder manifests as single or multiple filling defects at pyelography. This appearance of metastatic melanoma of the urinary tract has not been previously described in the roentgenologic literature. Recognition is important to prevent unnecessary intervention and to guide palliative treatment.