BACKGROUND: The aim of this study was to examine the expression of vascular endothelial growth factor receptor-2 (VEGFR-2) in Merkel cell carcinoma (MCC) and to correlate the expression with tumour growth and the development of metastasis. PATIENTS AND METHODS: The study included 21 patients treated for MCC at Helsinki University Hospital, Helsinki, Finland between 1987 and 2003. The VEGFR-2 expression was studied by immunohistochemistry. The correlations between the quantitative expression of VEGFR-2 and tumour size and metastatic dissemination were analyzed statistically. RESULTS: VEGFR-2 was expressed in 91% of the large (> or =2 cm) and 70% of the small (<2 cm) tumours. There was a stronger positive correlation between expression of VEGFR-2 and tumour size than between VEGFR-2 and metastatic potential. CONCLUSION: A correlation between the expression of pro-angiogenic marker and tumour size was established. Our results indicate that inhibiting angiogenesis could be a treatment option for MCC. The role of neovascularization in the metastatic process in MCC remains to be determined.