The thorax as the initial site for systemic relapse in malignant melanoma: a prospective survey of 324 patients.

Thirteen of 324 patients with malignant melanoma followed during a 24 month period experienced dissemination. The thorax was the initial site for relapse in 12, all of whom were asymptomatic. Ten gave no evidence of extrathoracic disease. Retrospective analysis of previous x-rays originally interpreted as negative revealed metastases in 33%. Life table analysis demonstrated a significantly longer survival for the subset with isolated intrathoracic metastases treated surgically than for their counterparts with metastases no longer amenable to surgery and treated by other modalities. We conclude that the thorax is the site of predilection for initial systemic relapse in malignant melanoma, that detection of early, surgically resectable metastases correlates with longer patient survival, and that routine chest roentgenography is inadequate in reliably uncovering such early disease. These data suggest the potential value of more vigorous radiographic surveillance (with either computed tomography or conventional full lung tomography) in patients at high risk for relapse.