A series of melanomas smaller than 4 mm and implications for the ABCDE rule

Background Although multiple studies have reported that a significant number of melanomas have diameters of less than or equal to 6 mm at the time of diagnosis, there has been only one series evaluating the proportion of melanomas less than 4 mm in diameter. Objective The objective of this study was to determine the proportion of melanomas, in a single-practitioner, general dermatology practice, with clinical diameters less than 4 mm. Methods information regarding each new diagnosis of melanoma had been recorded during the study period of 2000-2004. Patient records and pathology reports were examined from these patients. Results Thirteen (13.7%) of the 95 melanomas had diameters less than 4 mm at the time of presentation, including five invasive and eight in situ melanomas. The defining clinical characteristic of these lesions was intensity of pigment. Three of these 13 melanomas, including one invasive and two in situ lesions, showed features of regression. Conclusions The findings of this study support those authors who have suggested elimination of the 6-mm diameter criterion in the ABCDE rule. In addition, this study provides further evidence that dark colour as a diagnostic criterion for melanoma should be given more emphasis. The substitution of 'D' to represent dark instead of diameter is worthy of consideration to enhance the value of the ABCDE mnemonic.