Fig. 1

a Immunohistochemical characterization of 22 ENE-positive colorectal carcinomas. In each case, stromal positive lymphoid T cells were evaluated in five high-power fields (40×) in different areas of the samples: (i) central part of the primary CRC; (ii) invasive front of the primary CRC; (iii) intratumoral infiltration of the metastatic LN sample; (iv) intratumoral infiltration of the ENE positive LN sample; (v) invasive front of the ENE positive LN sample. A significantly higher percentage of CD4-, CD8- and CD68-positive cells was observed at the invasive front of both CRCs and in ENE in contrast with what observed at the core of both CRCs and their matched nodal metastases. ENE was also characterized by a significantly higher number of CD80-positive cells. (*p < 0.05; **p < 0.01; ***p < 0.001). b Representative images of CD80-positive cells distribution within the considered samples (original magnifications 20× and 40×; scale bars = 100 µm)