The morphologic diagnosis of analgesic (phenacetin) abuse.

A number of different morphologic characteristics were examined to determine their relative values in establishing a purely morphologic diagnosis of phenacetin abuse. These included hyperpigmentation of the skin, the costal cartilages, the liver, and the renal tubules, and capillarosclerosis of the lower urinary tract. Hyperpigmentation of the skin, liver, and renal tubules cannot be used in the diagnosis of phenacetin abuse. Massive brown pigmentation of the costal cartilages in patients under 60 years of age suggests phenacetin abuse, but even this morphologic parameter, when used alone, is insufficient to establish a definite diagnosis. Capillarosclerosis in the lower urinary tract does, however, permit one to diagnose phenacetin abuse with certainty, as it is found exclusively in this condition.