New insights in naevogenesis: number, distribution and dermoscopic patterns of naevi in the elderly

It is well recognized that the number and patterns of acquired melanocytic naevi vary with age, but little is known about naevus patterns in the elderly. This is a cross-sectional study assessing the prevalence, dermoscopic pattern and anatomical distribution of naevus subtypes in a stratified cohort aged between 60 and 89 years.

Fifty-nine patients who attended the Queensland Institute of Dermatology were recruited randomly and evenly distributed into three age groups: 60-69 years; 70-79 years; and 80-89 years. For each participant, total naevus count and morphological naevus types were recorded with respect to age, sex and anatomical location. Flat (Clark's) naevi were further subclassified according to the dermoscopic pattern as reticular, globular or structureless.

Using non-parametric methods, naevus counts in the elderly decreased due to the disappearance of reticular naevi (P < 0.05). By contrast, structureless and intradermal (Unna's and Miescher's) naevi seemed to persist even into older age. Naevi on the trunk, limbs, head and neck represented 57.6%, 31.0% and 11.3%, respectively. Notably, no reticular naevi were found on the head and neck area.

There is a progressive reduction in total naevus counts with advancing age with respect to a cohort aged greater than 60 years.