Comparing the different tumor types, CD8+ TILs were observed most frequently (60% of cases) in the adenocarcinoma subtypes HG-non-ITAC and solid-type ITAC, which is higher than previous studies on sinonasal tumors reporting 19–50% in SNSCC [24,25,26,41,42] and 19% in ITAC [22]. Here, CD8A is linked to adenocarcinoma.