Prognostic value of S100/CD31 and S100/podoplanin double immunostaining in mucosal malignant melanoma of the head and neck.

BACKGROUND In uncommon mucosal melanomas of the head and neck established prognostic factors are rare and controversially discussed. The purpose of this study was to evaluate outcome and value of S100/podoplanin and S100/CD31 double immunostaining in head and neck mucosal melanomas. METHODS Retrospectively, patients with head and neck mucosal melanomas treated between 1973 and 2008 were analyzed. S100/podoplanin and S100/CD31 immunostaining were performed to detect lymph vessel invasion (LVI) and blood vessel invasion (BVI). Predictive parameters for disease-specific survival (DSS) were identified using univariate and multivariate statistics. RESULTS Forty-two patients with head and neck mucosal melanoma were included. Three-year, 5-year, and 10-year DSS rates were 59%, 44%, and 20%, respectively. Age above 70 years, occurrence of distant metastasis, LVI, and BVI were significantly associated with shorter DSS time (p < .05), whereas localization at the conjunctiva showed better outcome. CONCLUSION S100/podoplanin and S100/CD31 double immunostaining detect reliable LVI and BVI in head and neck mucosal melanoma and both are associated significantly with worse prognosis.