The effect of misdiagnosis and delay in diagnosis on clinical outcome in melanomas of the foot.

BACKGROUND: Melanoma of the foot is often discussed as an uncommon tumor which, when it occurs, presents in nonwhite races. STUDY
DESIGN: The tumor registry of a 650 bed community teaching hospital and the Connecticut Tumor Registry were retrospectively reviewed for the nine-year period from July 1980 to July 1989. Patient age, race, sex, incidence of misdiagnosis, and delay until definitive therapy were recorded. Tumor location, size, staging, follow-up, recurrence, and disease-free survival rates were also recorded and correlated with initial disease, stage, and misdiagnosis or delay.
RESULTS: Twenty-six cases were identified at Bridgeport Hospital, and 140 cases were identified in the Connecticut Tumor Registry. Significant delay in diagnosis occurred in 68 percent of the cases from the hospital and at least 16 percent of the cases in the state tumor registry. Regardless of stage, melanoma of the foot had a worse prognosis than melanoma of the thigh and lower leg. Delays in diagnosis had no demonstrable effect on clinical outcome.
CONCLUSIONS: Melanoma of the foot is not as rare as commonly suspected, and constituted 3 percent of the 4,562 melanomas reported in the state tumor registry for the nine-year period. The majority were in fair-skinned individuals, and misdiagnosis was common. It is the inherent aggressiveness of the tumor rather than the delay in diagnosis that accounts for the poor clinical outcome.