Fig. 1

Semiquantitative evaluation of epithelial tumor-infiltrating lymphocytes (E-TILs) and stromal tumor-infiltrating lymphocytes (S-TILs). A–C Representative cases of CD3⁺ E-TILs, A high: > 10 immunopositive lymphocyte per high-power field (HPF) (×400) within the tumor cell nests, B intermediate: between high and low, C low: < 3 immunopositive lymphocytes per HPF, ×400. D–F Representative cases of CD3⁺ S-TILs, D high: zonal dense infiltration in over half length of the invasive front stroma area (arrows), E intermediate: focal nested infiltration (arrows), F low: entirely sparse infiltration (< 10% length), × 40