MELANOCYTIC LESIONS EXCISED FROM THE SKIN - WHAT PERCENTAGE ARE MALIGNANT

We estimated the diagnostic skill of clinicians managing melanocytic s kin naevi by measuring the percentage of malignant melanomas, premalig nant and potentially malignant naevi, in 1896 excised melanocytic lesi ons submitted to a pathology service over 11 weeks. They comprised 8 p er cent. The percentage increased with age: 4 per cent in the under-40 s, 17 per cent in those aged 40-59, and 30 per cent in those over 60, (P < 0.001, sex-adjusted). Although the percentage was twice as high i n males (II per cent) as females (6 per cent), after adjustment for ag e the difference was not significant. Invasive melanomas, 3 per cent o f the total, were similar: 1 per cent were from under-40s; 7 per cent from those aged 40-59 years; and 14 per cent from those over 60. They comprised 4 per cent of lesions from males and 2 per cent from females . These trends may indicate pow specificity of clinical diagnosis, not withstanding other reasons for removal of naevi (cosmetic), particular ly among patients under 40, and females.