Aid to diagnosis of melanoma in primary medical care

Objective : To evaluate an intervention designed to reduce the number of benign melanocytic lesions excised from the skin. Design : A randomised controlled field trial based in the medical practices of two cities. Examination of histopathological reports of 5823 melanocytic skin lesions excised over the intervention period and in the preceding six months Intervention : Medical practitioners were offered an algorithm and use of an instant developing camera. Setting and subjects : Over 50 medical practitioners, mostly in general practice, in each of two cities in tropical Queensland, Australia. Main outcome measures : Percentages of benign (neither malignant nor potentially malignant) melanocytic lesions excised during the two year intervention period. Results : There were no significant differences in the percentages of benign lesions reported in the intervention and control cities before the intervention started (93.6% and 94.0%, respectively), but there was a significant difference afterwards (88.8% and 93.8%, P<0.001). There was no difference in the percentage of invasive melanomas excised per month in the intervention city (3.4%) compared with control city (3.4%). Conclusion : Clinical diagnostic accuracy may be enhanced by offering to clinicians managing suspicious melanocytic skin lesions a simple algorithm and a camera with which to record the appearance of lesions objectively. Key messages Key messages To avoid missing a diagnosis of melanoma many benign pigmented skin lesions are excised Unless obviously malignant initially a lesion for which malignancy cannot be excluded may be watched if its size and appearance can be accurately recorded so that any change is detected with follow up An instant camera and a simple algorithm may reduce false positive excisions without increasing false negative diagnoses in populations susceptible to malignant melanoma Use of an instant camera and an algorithm is relatively easy to incorporate into usual clinical practice