The rational clinical examination. Does this patient have a mole or a melanoma?

Lifetime risk for malignant melanoma has increased from 1 in 1500 in the United States in 1930 to 1 in 75 projected for the year 2000. Because the tumor's thickness at excision is the primary prognostic determinant, early detection through the history and physical examination can play an important role in the patient's clinical course. Two checklists have been developed as diagnostic aids, the ABCD (A indicates asymmetry; B, border irregularity; C, irregular color; and D, diameter >6 mm) and the revised 7-point checklists. These checklists should be interpreted with some discretion, but 2 studies have found the sensitivity for the ABCD checklist to be 92% (95% confidence interval [CI], 82%-96%) and 100% (95% CI, 54%-100%); 1 study found the specificity to be 98% (95% CI, 95%-99%). The revised 7-point checklist has been reported to have a sensitivity of 79% (95% CI, 70%-85%) to 100% (95% CI, 94%-100%) and specificity of 30% (95% CI, 21%-39%) to 37% (95% CI, 28%-46%). Physicians' global assessments for detecting the presence or absence of melanoma are estimated to have a specificity of 96% to 99%, while sensitivity ranges widely from 50% to 97%. Nondermatologists' examinations appear to be less sensitive than examinations performed by dermatologists.