Extrafacial lentigo maligna melanoma: analysis of 71 cases and comparison with lentigo maligna melanoma of the head and neck

We report a retrospective analysis of extrafacial lentigo maligna melanoma (LMM), and a comparison with patients with LMM of the head and neck. Seventy-one patients (22 men, 49 women) with extrafacial LMM were identified from the Scottish Melanoma Group database for January 1979-March 1996. Their mean age (63 years) was significantly less than that of 335 patients with head and neck LMM (mean 72 years, P < 0.001), with a significantly greater difference among women than men. Extrafacial sites comprised 17.5% of LMMs. There was a marked body site distribution difference between the sexes (P = 0. 001): 68% of extrafacial LMMs in men were on the trunk while 80% in women were on the limbs, particularly the lower leg. Extrafacial LMMs were thinner at presentation than head and neck LMMs (P < 0.05) in both sexes, but this was not simply explained by the younger age of these patients as there was no significant correlation between age and tumour thickness at either extrafacial or at head and neck sites. Although the female lower leg is a site of chronic solar exposure in older women, the other extrafacial sites are habitually covered in the temperate Scottish climate. The significantly younger age group of patients with LMM at extrafacial compared with head and neck sites therefore suggests that the relationship between LMM and sunlight is not simply related to cumulative solar exposure. The demonstration that head and neck LMMs were thicker at presentation compared with extrafacial sites, despite being at a more routinely visible part of the body, suggests that there are still opportunities for targeted pigmented lesion public education.