A facial skin lesion
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| 1. What is this facial skin lesion? |
| 2. How would you manage it? |
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This facial skin lesion is a basal cell carcinoma. They are the commonest skin cancer and the most frequent malignancy in Caucasians. They are rare in dark skinned races. The highest incidence is found in populations exposed to high levels of ultraviolet light (e.g. Australia) where the incidence is up to 1/100/yr. and increasing. A Caucasian in that climate has a life-time risk of developing a BCC of 25-30%. Despite the high incidence of these tumours the mortality is low - an order of magnitude less than that of malignant melanoma. Early BCCs appear as translucent, pearly nodules with dilated surface vessels. As they increase in size they display typically rolled edges and telangiectasia are common. 80% occur on the face above an imaginary line from the mouth to the ear. Most are indolent with slow growth and they rarely metastasize. The differential diagnosis should include other cutaneous malignancies e.g. squamous cell carcinoma, melanoma, psoriasis, eczema, sebaceous hyperplasia and solar keratosis. Predisposing factors include albinism, xeroderma pigmentosa, ultraviolet light and arsenic toxicity. The naevoid basal cell carcinoma syndrome (Gorlin's syndrome) consists of multiple BCCs usually occurring < 30 yrs, dental cysts, spina bifida, bifid ribs, hypertelorism and syndactyly. This is an autosomal dominant condition with a linked locus on 9q. Several treatment options exist. These include:
The exact management will depend on the site and size of the lesion, the age of the patient, cosmetic considerations and doctor and patient preferences. There are no large randomised controlled trials comparing treatment modalities. In the United kingdom surgical treatment is the most common. 80% of lesions are removed with primary closure. Over 95% are cured by adequate surgery. Resection margins of <5 mm and the use of currettage are associated with an increased risk of recurrence. In 1939 Fredrick Mohs described fixation of skin cancers in-situ followed by systematic excision and pathological mapping. Surgery was repeated until a margin of normal tissue was obtained. Recent modifications have removed the need for lesion fixation. This slow and prolonged technique has resulted in cure rates of over 97% . It is particularly useful for morphoeic BCCs where the margins of the lesion can be difficult to see with the naked eye. Radiotherapy is useful in the elderly as it does not involve the risks of anaesthesia. It is particular useful in difficult sites - nose, eye, ears where extensive flaps would be required in order to achieve wound closure. The margins of the lesion are not critical. Increased fractionation produces better cosmetic results but makes treatment prolonged and expensive. There is the risk of radiation necrosis of the skin. Less than 5% of BCCs recur after initial treatment. Factors associated with recurrence are increased tumour size, involved histological margins and certain growth patterns (e.g. morphoeic BCCs). Treatment can be difficult and the results less assured than after primary therapy. Less than 1 in 200 BCCs metastasize. In those with metastatic disease the 5 year survival rate is about 10%. Recent papersLear J T, Smith A G. Basal cell carcinoma. Postgrad Med J 1997; 73: 538-542 Holt P J A, Motley R J. The treatment of basal cell carcinoma. Curr Surg Pract 1994; 6: 98-101 Telfer N R, Colver G B, Bowers P W. Guidelines for the management of basal cell carcinoma. Br J Dermatol 1999; 141: 415-423.
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