The pathophysiology and staging of cutaneous malignant melanoma.

The incidence of cutaneous malignant melanoma is increasing by 10% a year and by as much as 30% a year among whites living in the sunbelt. If present trends continue, it will soon be one of the most common cancers occurring in fair-skinned individuals who have sustained severe sunburns. Although sunlight is the major cause of melanoma, several other factors, such as hormones, have also been implicated. Malignancy should be suspected in any pigmented lesion that changes in color or size, begins to itch, or bleeds or oozes spontaneously. Because of these characteristic and often highly visible changes, the disease can usually be diagnosed when surgically curable. Microstaging allows prognostic categorization of risk, with thickness the single most important prognostic factor for patients with disease clinically limited to the primary site. Staging also determines the treatment plan.