Tumor vascularity and tryptase-positive mast cells correlate with a poor prognosis in melanoma

Background The importance of angiogenesis in melanoma has been controversial and is not homogeneous. Mast cell density (MCD) is highly correlated with the extent of both normal and pathological angiogenesis, such as that in chronic inflammatory diseases and tumours. Methods We evaluated the prognostic significance of tumour microvascular density (MVD) and MCD in 25 advanced melanoma patients after resection and a 4-5-year follow up: 48% of the patients were alive and free of metastases (good prognostic subgroup); 16% had developed regional nodal metastases (intermediate prognostic subgroup); and 36% had died (poor prognostic subgroup). Tissues samples were investigated immunohistochemically to count microvessels and mast cells with an antifactor VIII and an antitryptase antibody, respectively. Results Immunohistological staining showed a higher number of microvessels and mast cells in melanoma lesions of poor prognosis as compared with intermediate prognosis and with good prognosis, respectively. Conclusions These data agree with those showing a close relationship between MCD and angiogenesis during tumour progression and demonstrate, for the first time, a prognostic significance of MCD in human melanoma.