Prognostic significance of histopathology of primary conjunctival melanoma in Caucasians

Purpose: To assess histopathologic prognostic factors relative to clinical ones in predicting local recurrence and survival after primary conjunctival melanoma (CM). Methods: 85 patients with CM were identified in Finland between 1967 and 2000, and 70 primary tumors were available for histopathologic study. Time to first recurrence and melanoma-related mortality were analyzed. Results: Absence of epithelioid cells (P = 0.033), smaller mean diameter of the ten largest nucleoli (P = 0.041) and increasing mitotic count (P = 0.042) were associated with shorter time to recurrence. The mean diameter of the ten largest nucleoli, the number of tumor-infiltrating lymphocytes and macrophages, extravascular matrix loops and networks, and microvascular density were unassociated with recurrence. Nonlimbal location (P = 0.001), recurrence (P < 0.001), and increasing tumor thickness (P = 0.007) were associated with mortality. By multivariate Cox regression, a model including recurrence and tumor location fitted best with mortality data. Conclusions: Histopathological factors are not consistently associated with survival in CM. Tumor location, thickness, and recurrence are predictors of mortality from CM.