More medullary sponge variants

Sponge kidney has characteristic plain film and urographic findings which are generally regarded as being limited to the medullary pyramids. We describe two groups of patients with renal changes of medullary sponge kidney who show additional renal abnormalities. In the first group there were multiple cortical cysts; in the second there were cavities deep in the medulla, many of which communicated with the calices. Neither of these findings has been described before and we suggest that the spectrum of changes associated with this condition is wider than has previously been appreciated.