Emphysematous pyelonephritis: report of 4 cases.

Emphysematous pyelonephritis is a rare, life endangering suppurative infection of the renal parenchyma and perirenal spaces. The disease is encountered mainly in patients with diabetes mellitus and is characterized by the production of intrarenal and, occasionally, perirenal gas. We present 4 cases of emphysematous pyelonephritis encountered in our hospital with review of the literature.