Patterns of excision and referral from primary care of melanocytic lesions.

There is debate about the margin of normal tissue that should be included with excisions of melanocytic lesions of the skin, and about which lesions should be referred for specialist care. We describe the determinants of the margins of excised melanocytic skin lesions and of referral patterns from primary care. Copies of the pathology reports of melanocytic skin lesions excised from two cities in tropical Queensland were obtained; questionnaires about each lesion were administered to the excising doctor. Data about 3275 lesions (2914 naevi, 130 lentigos, 151 melanomas, 51 dysplastic naevi, 21 Hutchinson's melanotic freckles and eight other melanocytic lesions) were analysed. Twenty-one per cent of the treatment sessions involved the excision of more than one lesion; 5% involved three lesions or more. Most lesions were managed by one doctor. The overall mean margin of excision was 2.8 mm. It was greater for longer qualified doctors, surgeons and college-affiliated general practitioners, for lesions excised to address malignancy (3.0 mm) rather than cosmetic appearance (2.4 mm), for Hutchinson's melanotic freckles (5.9 mm) and melanomas (5.1 mm) compared with benign lesions (2.7 mm) (P < 0.001) and for older patients (2.6 mm for those < or = 15, 3.5 mm for those > 40 years) (P = 0.001). Wider excisions of skin melanocytic lesions are performed by older and more experienced doctors, on older patients, and for lesions in which malignancy is being addressed.