Benign tumours
Skin tumours are common, and their incidence is rising in western countries (p. 24). The treatment of skin tumours makes up a large part of current dermatological practice (p. 24). Many skin tumours are benign, and these are described in this section. Viral warts, actinic keratoses and naevi are mentioned elsewhere.
Benign epidermal tumours
Seborrhoeic wart (basal cell papilloma)
A seborrhoeic wart (seborrhoeic keratosis) is a common, usually pigmented, benign tumour consisting of a proliferation of basal keratinocytes (Fig. 1). The cause is unknown, although they may be ‘naevoid’. Seborrhoea is not a feature.
Clinical presentation
Seborrhoeic warts have the following features:
often multiple (Fig. 2), sometimes solitary
affect the elderly or middle-aged
mostly found on the trunk and face
generally round or oval in shape
start as small papules, often lightly pigmented or yellow
become darkly pigmented warty nodules, 1–6 cm in diameter
have a ‘stuck-on’ appearance, with keratin plugs and well-defined edges.
Skin tags
Skin tags are pedunculated benign fibroepithelial polyps, a few millimetres in length. They are common, mainly seen in the elderly or middle-aged, and show a predilection for the neck, axillae, groin and eyelids (Fig. 3). The cause is unknown, but they are often found in obese individuals. Occasionally, skin tags are confused with small melanocytic naevi or seborrhoeic warts. The treatment, usually for cosmetic reasons, is by snipping the stalk with scissors or cutting through it with a hyfrecator (under local anaesthetic if necessary), or using cryotherapy.
