Transitional cell carcinoma of the kidney.

Transitional cell carcinoma is an uncommon disease of the renal pelvis, the diagnosis of which depends largely upon radiological investigation. Thirty-eight such tumours in 37 patients have been reviewed to establish the examination of choice. High-dose excretion urography, tailored to the presenting problems, is the primary investigation and the results fall into five main groups. Each presents different differential diagnostic problems. Discrete filling defects within the pyelogram (group I) may be overlooked, but, when seen, can be diagnosed on urography alone. Filling defects with dilated calyces (group II) are easily seen and readily diagnosed. Calyceal obliteration (group III) presents more difficulty in diagnosis and may require retrograde pyelography and selective renal angiography. Hydronephrosis with renal enlargement (group IV) is easily confused with uncomplicated primary pelvic hydronephrosis and will usually require antegrade pyelography for diagnosis. Reduced function without renal enlargement (group V) cannot be diagnosed on excretion urography and requires both retrograde pyeloureterography and selective renal angiography.