Immunopathological evaluation of oral squamous cell carcinomas: a case series

The evaluation of the expression of programmed cell death protein (PD-L1) is an eligibility criterion for anti-PD-L1 immunotherapy in oral squamous cell carcinoma (OSCC). Other components of tissue microenvironment should also be evaluated. Here, four cases of oral squamous cells carcinoma were reported. Histopathological analysis of tumor grade and TILs and immunohistochemistry for CD4, CD8, and PD-L1 was done. The cases were classified according to the tissue microenvironment in adaptive immune resistance, immunological ignorance, tolerance, or intrinsic induction. This analysis highlights the importance of understanding the immunological microenvironment that the OSCC can present for the identification of more effective therapeutic targets against the disease.