Small melanomas: a clinical study on 270 consecutive cases of cutaneous melanoma

The ABCD (asymmetry, border, colour, dimension) criteria represent a common ly used clinical guide for the diagnosis of early cutaneous melanoma (CM), This guide stipulates that CMs usually are more than 6 mm in diameter. The purpose of this retrospective study was to establish the frequency of occur rence of small (less than or equal to 6 mm) melanomas in a clinical context . Our series consisted of 270 consecutive CMs (39 in situ and 231 invasive) in 267 patients. Of these 270 lesions, 47 (17%) were small lesions, rangin g from 2 to 6 mm in maximum linear extent, with a median value of 5 mm. Of these small lesions, 14 were in situ and 33 invasive CMs. The median thickn ess of the 33 small invasive lesions was 0.31 mm, The clinical features of CMs were sufficiently distinctive to suggest a diagnosis of CM in half of t he cases, irrespective of the invasiveness or not of the lesions. Dermatosc opy was performed on 36 of the small lesions and achieved a correct diagnos is in 72% of the cases. The combination of simple visual examination with d ermatoscopy allowed a higher rate of recognition (86%) than when the two me thods were considered separately. Results of our study show that small CMs represent a considerable clinical subset of all CMs. Clinicians must be awa re of this fact in their diagnostic activity. (C) 1999 Lippincott Williams & Wilkins.