Dermoscopic naevus patterns in people at high versus moderate/low melanoma risk in Queensland

Dermoscopic understanding of naevus characteristics is essential baseline knowledge for identifying early malignant changes.

This cross-sectional study includes 34 patients (56% female, mean age 48 years) at high risk of melanoma (personal or a first degree family member with history of melanoma) and 31 moderate/low melanoma risk volunteers (55% female, mean age 37 years) recruited at the Princess Alexandra Hospital, Brisbane, between October 2009 and March 2010. Participants received full body and individual dermoscopic imaging of clinically significant naevi (≥2 mm on the back of male/female and lower limbs of female and ≥5 mm at other body sites). Dermoscopic patterns of naevi were compared between people at high versus moderate/low melanoma risk according to age and body site.

In both high and moderate/low risk groups, globular naevi predominated on the head/neck and abdomen/chest, reticular and non-specific naevi on the back, and non-specific pattern on the upper and lower limbs. Non-specific naevi were the most common in all age groups. In both risk groups, globular naevi were more frequent in the younger age bracket, and reticular naevi were more frequent in the older age bracket. Mixed naevus patterns were infrequent and were more common in the younger age brackets of both risk groups.

Our preliminary data shows that dermoscopic naevus patterns were similar for age and body site in people at different levels of melanoma risk, suggesting high melanoma risk does not influence dermoscopic naevus patterns.