The aetiology of renal medullary necrosis: A survey of adult cases in Liverpool

Analgesic nephropathy

“…At the tip of the papilla, all the tubules may appear like this but the extent and the margin of the necrotic zone are variable. In the cases in which the necrosis has developed slowly without infection or episodes of circulatory failure, the necrotic area merges gradually with the viable stump of the medulla with no clear line of demarcation (fig 4), unlike that found in the more acute forms of renal papillary necrosis induced by such events as urinary obstruction (Schourup, 1957;Davies, Kennedy, and Roberts, 1970). However, the form taken by the necrosis is not constant, and, while an ill defined area, ie, Schourup's type II, is usual, more clearly demarcated lesions (type I) may be found, especially in cases where renal function has failed abruptly.…”

“…However, the form taken by the necrosis is not constant, and, while an ill defined area, ie, Schourup's type II, is usual, more clearly demarcated lesions (type I) may be found, especially in cases where renal function has failed abruptly. Thus, no one type of necrosis is specific (Burry, 1970;Davies et al, 1970).…”

“…In spite of this, the frequency of recognition in different countries has varied considerably, and a retrospective study by pathologists who are specially interested in the condition may reveal few cases (Davies et al, 1970). There are several reasons for this of which the first is the reliability of the history of the drugs taken.…”

“…The characteristic feature of analgesic nephropathy is the presence of renal papillary necrosis but this may have a number of causes other than drug abuse, notably urinary obstruction, diabetes, renal vein thrombosis, and pyelonephritis (Schourup, 1957;Jacobs and Morris, 1962;Bengtsson, 1962;Harvald, 1963;Burry, de Jersey, and Weedon, 1966;Davies et al, 1970). The cautious pathologist is usually unwilling to attribute a lesion to the effect of a drug when there is some natural explanation available.…”

“…Different variants of papillary necrosis have been described (Schourup, 1957;Davies et al, 1970). These fall into two types: acute infarct-like lesions and bland ill-defined areas of necrosis which merge gradually with the viable stump of the medulla.…”