Abnormal vessels in the urinary tract following analgesic abuse in man.

A brownish discoloration of the bladder mucosa around the ureteric orifices has been observed on cystoscopy in three patients taking excessive quantities of analgesics. Biopsy specimens revealed an unusual degree of hyalinization of the vessels in the submucosa. Similar changes have been noted in the renal medulla, pelvis, and ureter of patients with classical analgesic nephritis. This vascular change may play an important part in the development of the characteristic infarct-like necrosis seen in the analgesic kidney.