Outcome of patients with de novo versus nevus-associated melanoma.

BACKGROUND: Prior reports indicate a wide range of melanomas in histopathologic contiguity with a nevus, and an associated nevus has unclear prognostic implications in melanoma.

OBJECTIVE: We sought to investigate the relationship among nevus-associated melanomas, sentinel lymph node status, and overall survival.

METHODS: We conducted a retrospective analysis of 850 patients with cutaneous melanoma and sentinel lymph node removed at Massachusetts General Hospital from 1998 through 2008 and meta-analysis of the literature.

RESULTS: Nevus-associated melanomas represented 28% (235/850) of cases and were significantly correlated with younger age (P = .03), truncal site (P = .0005), superficial spreading type (P < .0001), and absent ulceration (P = .005). There was no association with sentinel lymph node status (P = .94) and no survival difference between nevus-associated versus de novo melanoma (P = .41). Meta-analysis of over 4000 cases revealed a similar percentage of associated nevi (32%).

LIMITATIONS: This was a retrospective study.

CONCLUSIONS: Approximately 30% of melanomas are associated with a nevus. The presence of a nevus associated with a melanoma has no prognostic implication in sentinel lymph node status or overall survival.