Small-diameter malignant melanoma: a common diagnosis in New South Wales, Australia

Abstract

Background: The "ABCDE" guide developed at the New York University Medical Center and Harvard Medical School has proved useful in the detection of early malignant melanomas. This guide stipulates that melanomas usually are more than 6 mm in maximal diameter and are elevated.

Objective: Our purpose was to determine whether these size criteria applied in Australia.

Methods: The records of 1150 melanoma patients at the Sydney Melanoma Unit between June 1989 and September 1991 were reviewed.

Results: Almost one third of the 1150 melanomas (358) were 6 mm or less in maximal diameter, and the median thickness of these 358 melanomas was 0.8 mm.

Conclusion: The "ABCDE" guide to the signs of early melanoma may have to be modified to include smaller diameter, clinically impalpable melanomas. There appears to be a close correlation between patient age at diagnosis and both lesion diameter and thickness. Because increases in diameter occurred more rapidly than increases in thickness, subtle increases in lesion diameter may provide a better clue to earlier diagnosis.