Peritumoral inflammatory reaction in colon cancer. Histological and immunohistochemical study.

Abstract Colorectal cancer is one of the most frequent malignancies with an increasing incidence and prevalence. As in other malignancies, nor etiology, neither pathogenesis of colorectal cancer are well known. The link between inflammation and colorectal cancer has become a major concern in the past 20 years, since several clinical trials have shown that patients with chronic inflammatory intestinal diseases have a much higher risk of colorectal neoplasm development. In our study, we analyzed peritumoral inflammatory reaction from histological and immunohistochemical point of view, in 23 cases of stage III colon adenocarcinoma, operated during 2014. The immunohistochemical techniques were used in order to emphasize B-lymphocytes, T-lymphocytes, macrophages, mast cells and blood vessels. In all cases, we have noted the involvement of inflammatory cells present in peritumoral and tumoral stroma, in variable degrees, regardless the differentiation of the neoplasm or other known histological feature. In particular, the macrophages were the most numerous, especially in areas of tumoral necrosis, but also present in the lumen of tumoral glands, or even within tumoral cell islands. Mast cells appeared more abundant in the tumor stroma around blood vessels and were absent in the areas of tumor necrosis, while B-cells were almost absent. Tumor stroma showed a well-developed vascular network, consisting mainly of small vessels that do not seem to correlate with the intensity of the inflammatory reaction.