Classic diseases revisited Basal cell carcinoma

JT Lear, AG Smith Summary Basal celi carcinoma is the commonest malignancy in Caucasians with incidence rates of 300 per 100 000 reported in the USA. Rates are increasing at over 10% per year leading to a lifetime risk of 30%. Although mortality is low, the disease is responsible for considerable morbidity and places a substantial burden on health service provision in the UK. Furthermore, lesions may recur and patients often develop multiple tumours giving major implications for treatment and followup. Four main types of basal cell carcinoma are seen: nodulo-ulcerative; pigmented; morpheaform and superficial. Diagnosis is by histological evaluation although many tumours have a characteristic clinical appearance. The differential diagnosis is large. Identified risk factors include male gender, skin type 1, red/ blonde hair and increasing age. Patients with basal cell carcinoma are more likely to develop malignant melanoma and squamous cell carcinoma but it is still unclear whether there is a link with internal malignancy. The main treatment modalities are surgery and radiotherapy. Each has advantages and disadvantages. The choice of treatment depends on many factors. Principles of treatment include identification of high-risk patients to enable early detection, complete removal of the lesion, and careful follow-up to detect recurrence or new lesions. Approximately 10% of tumours recur, depending on site, size and treatment modality. Metastatic basal cell carcinoma and the association of ultraviolet radiation to basal cell carcinoma risk are reviewed.