Features
Intra-dermal naevi are formed when junctional melanocytes stop proliferating and the overlying skin returns to normal. They commonly develop from previously existing compound naevi.
Clinically, intra-dermal naevi are raised, non-pigmented nodules which can appear as flesh coloured skin tags. Lesions often display visible capillaries, and terminal hair growth. They are most commonly found on the face.
The other type of intra-dermal naevus appears as a flesh coloured, wrinkly sac between 5mm and several centimetres in diameter. These are usually present on flexor surfaces of the limbs and trunk of older individuals.
Incidence
Very common. These tend to develop from compound naevi, so the incidence is similar for both groups.
Aetiology
Overgrowth of cells in the dermis of unknown aetiology.
Differential Diagnosis
Basal cell carcinoma. Neurofibroma. Nodular melanoma.
Treatment
None required. Lesion can be excised if causing cosmetic concern. Lesions may also be removed to determine/confirm diagnosis by histology.