PD-L1 Expression, T-lymphocyte Subpopulations and Langerhans Cells in Cutaneous Squamous Cell Carcinoma and Precursor Lesions.

Background/aim: The role of immune cells and PD-L1 in cutaneous squamous carcinogenesis is unclear. This study examines T-cell populations, Langerhans cells (LCs) and PD-L1 in invasive squamous cell carcinoma (inSCC), adjacent precursors and normal skin (NS) to investigate their participation in tumorigenesis.

Materials And Methods: Cases of cutaneous inSCC with adjacent precursors (n=125) were selected.

Evaluation of T-lymphocyte subpopulations in actinic keratosis, in situ and invasive squamous cell carcinoma of the skin.

Background: Tumor infiltrating lymphocytes (TILs) represent important regulators of carcinogenesis. Cutaneous invasive squamous cell carcinoma (inSCC) develops through precursor lesions, namely in situ squamous cell carcinoma (isSCC) and actinic keratosis (AK), representing a natural model of carcinogenesis. The study evaluates TIL subpopulations in inSCC and its precursors by comparing 2 semiquantitative scoring systems, and assesses the presence of regulatory T-cells (Tregs) in these lesions.