Increased tumour cell <scp>PD</scp>‐L1 expression, macrophage and dendritic cell infiltration characterise the tumour microenvironment of ulcerated primary melanomas

Abstract

Our results confirm the adverse clinical outcome associated with primary melanoma ulceration, particularly concerning the risk of recurrence and subsequent development of brain metastases. The observed immunological differences suggest a conceivable role of increased intratumoural macrophage and dendritic cell counts associated with enhanced tumour cell PD-L1 expression potentially contributing to the immunosuppressive, growth-promoting microenvironment of ulcerated primary melanomas.