Skin tumours in White South Africans. Part III. Distribution of skin tumours on the body.

The distribution of the commoner skin tumours is detailed according to body site. Cutaneous horns, keratoacanthomas, Bowen's lesions and squamous and basal cell carcinomas occur mainly on exposed areas, confirming the importance of sunlight in their causation. However, a quarter of the Bowen's and over half the superficial basal cell carcinoma lesions are seen on covered areas, indicating that these tumours are both distinct entities. That seborrhoeic keratoses, intradermal and compound naevi, haemangiomas and lentigines were most often seen on the face may simply reflect the fact that patients often seek cosmetic help for these complaints. Distributional analysis suggests that cellular naevi on the trunk are much more likely to cause malignant melanoma than those on exposed areas.