Clinical presentation:
incidental finding in an adult male.

The intravenous urogram shows large kidneys, being significantly larger than the usual 3 vertebral bodies. The renal borders are smooth. The calyceal pattern appears normal, apart from contrast collections within the renal papillae. The contrast density appears to be a fan of small lines that radiate from the calyces in the expected location of the collecting tubules, but large enough to be seen. Occasional local dilatations or additional contrast densities are seen in-relation to these lines. The appearance implies a general enlargement of the collecting ducts within the renal papillae.

There was no calcification on the plain film.