Selective immunohistochemical staining shows significant prognostic influence of lymphatic and blood vessels in patients with malignant melanoma

Few data on the influence of lymphatic microvessel density (LMVD) on survival in patients with melanoma are available. The aim of this study was to assess LMVD and blood microvessel density (MVD) in tissue samples from 120 patients with melanoma. LMVD was stained with an antibody staining for podoplanin, and blood MVD was assessed by CD31 (PECAM-1)-immunostaining. Survival was determined using univariate and multivariate analysis. A significant association between a high CD31 MVD (but not LMVD) and the presence of lymph node metastases (P=0.007) was observed. Patients with a high LMVD had a significant shorter overall (OS) (P=0.0436) and disease-free survival (DFS) (P=0.0249) in univariate analysis. The survival analysis showed CD31 MVD was a strong prognostic factor for OS and DFS in both uni-and multivariate analyses. Our results demonstrate LMVD as a prognostic factor in malignant melanoma, although its prognostic relevance is much smaller compared with blood MVD.