Skin tumours in White South Africans. Part I. Patients, methods and incidence.

A survey of all skin tumours recorded in Whites in a dermatological practice in the southern Transvaal is presented. Nearly a quarter of the 15 000 consecutive patients seen over a period of 7 years complained of skin tumours. They were considered to be a representative sample of the population, since their occupations compared well with those of White South Africans in general. The relative frequency of skin tumours is shown in detail. Sun-induced tumours are common, solar keratoses occurring in 10% of all patients, basal cell carcinomas in 4%, kerato-acanthomas in 1% and squamous cell carcinomas in 0,5%. Seborrhoeic keratoses, cellular naevi, polyps, cysts, angiomas and histiocytomas are also commonly seen; patients with these complaints often seek medical advice for cosmetic reasons.