Blue Naevus
A blue naevus on the cheek of an adolescent. In this case, the concern related to cosmetic appearance.
This is a close-up of the same lesion shown in Figure 1. Note the clear borders and raised appearance of the lesion.
This blue naevus is more nodular and darkly pigmented than those shown in the preceding figures.
Features
A Blue naevus is defined as an area of blue or blue-black dermal pigmentation produced by aberrant collections of pigment-producing but benign melanocytes. They are usually found on the extremities such as on the dorsum of the hands and feet, the face and the buttocks. The lesion may be present from birth, but most often appear during puberty.
Clinically, blue naevi are non-tender, slightly raised, occassionally nodular, blue/blue-black lesions with obvious borders.
Incidence
Relatively common. There is a higher prevalence in the Asian population (3-5%) than the white population (1-2%). Blue naevi are thought to be more prevalent in women (2.5:1), but this may reflect higher levels of anxiety and cosmetic dissatisfaction in women compared to men.
Aetiology
Collection of pigment producing benign melanocytes of unknown aetiology.
Differential Diagnosis
Malignant melanoma. Melanocytic naevus. Compound naevus. Lentigo.
Treatment
None required. If causing concern for cosmetic reasons, excsion may be considered. Lesions are often removed to rule out melanoma.
