Benign non-melanocytic skin lesions
- Identify and describe common congenital and acquired non-melanocytic skin lesions
- Naevi consist of clusters of epidermal or dermal cells with numerous clinical variants.
- Seborrhoeic keratoses (basal cell papillomas) appear as stuck-on warty plaques and are very common in those over 40 years of age.
- Epidermoid cysts are walled-off cavities filled with keratin and are derived from the hair follicle unit.
- Syringomas are sweat duct tumours most often presenting as skin-coloured papules on the eyelids.
- Dermatofibromas are firm dermal papules caused by a proliferation of fibroblasts.
- Skin tags are pedunculated papillomas filled with loose collagen.
- Keloids are scars with excessive bands of collagen.
- Lipomas are due to a proliferation of adipose tissue and present as soft subcutaneous nodules.
- Neurofibromas are spindle cell tumours and present as soft to firm dermal nodules.
- Vascular tumours in babies may be proliferative haemangiomas, which usually resolve, or vascular malformations including port wine stain and lymphangioma circumscriptum.
- Pyogenic granulomas are formed of granulation tissue (vascular proliferation with inflammatory infiltrate).
Common benign non-melanocytic tumours are described on DermNet.