NECROSIS of the renal papillae, sometimes termed "papillitis necroticans"1 or "necrotizing pyelonephritis,"2 is an infrequently recognized and severe type of suppurative renal infection that is usually encountered in diabetic patients although it is occasionally found in nondiabetic persons.3,4 The lesion, which has been a well recognized pathologic entity for many years, was recently well described by Günther.5 It remains, however, a poorly defined clinical entity that is usually found as an unexpected lesion at autopsy. Recent publications emphasize the fact that the problem of acute pyelonephritis — in particular that of necrotizing papillitis — is of greater magnitude than its . . .