Rom J Morphol Embryol 2014, 55(4):1429–1435 ISSN (print) 1220–0522 ISSN (on-line) 2066–8279 ORIGINAL PAPER Peritumoral inflammatory reaction in colon cancer. Histological and immunohistochemical study STELIAN ŞTEFĂNIŢĂ MOGOANTĂ 1) , CORINA LUNGU 2) , CĂTĂLIN ILIE 2) , DINU FLORIN ALBU 3) , BOGDAN TOTOLICI 4) , CARMEN NEAMŢU 4) , PAUL MITRUŢ 5) , CARMEN ADRIANA DOGARU 6) , ADRIANA TURCULEANU 7) 1) Department of Surgery, Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, Romania 2) Department of Functional Sciences, University of Medicine and Pharmacy of Craiova, Romania 3) Department of Obstetrics and Gynecology, “Carol Davila” University of Medicine and Pharmacy, Bucharest, Romania 4) Department of Surgery, Faculty of Medicine, Pharmacy and Dental Medicine, “Vasile Goldiş” Western University, Arad, Romania 5) Department of Internal Medicine, University of Medicine and Pharmacy of Craiova, Romania 6) Department Family Medicine, Faculty of Medicine, University of Medicine and Pharmacy of Craiova, Romania 7) Department of Microbiology–Immunology, University of Medicine and Pharmacy of Craiova, Romania 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. Keywords: colon cancer, inflammatory cells, chronic inflammation, mast cells, macrophages.  Introduction Colorectal cancer (CRC) is one of the most commonly diagnosed malignancies worldwide [1]. According to some authors [2], CRC is the fourth in men and third in women as frequency, with a mortality that ranks second after lung cancer [3], resulting in over 800 000 related deaths each year. Worldwide reports show slightly rising incidence both in men and women. Relatively recent studies counted around 102 900 cases of colon cancer and 39 670 cases of rectal cancer newly diagnosed only in the US in 2010; approximately 51 370 patients died from CRC in the same year, repre- senting approximately 9% of all cancer-related deaths [4]. As in other malignancies, nor etiology, neither patho- genesis of colorectal cancer are not very clear. A number of factors were considered important in causal relation- ship, such as adenomatous polyps, hereditary syndromes (familial adenomatous polyposis, hereditary non-polyposis colorectal cancer – Lynch syndrome), inflammatory bowel disease, diet, smoking, lifestyle, etc. The link between inflammation and cancer is a relatively recent concern, although since 1863 Virchow showed that different cancers were detected in areas of chronic inflammation [5]. Furthermore, many clinical and epidemiological studies demonstrated that chronic inflammatory intestinal diseases, namely ulcerative colitis and Crohn’s disease have an increased risk of malignant degeneration [6–10]. Recent evidence suggests that between inflammation and cancer there is a close relation- ship, the malignant cells being capable of inducing a local or systemic inflammation, the activation of transcription factors and major inflammatory cytokine production [11]. In turn, inflammation associated with cancer may influence cell proliferation and survival, angiogenesis, tumor cell migration, invasion and tumor metastasis [11]. In this study, we have proposed to identify inflam- matory cells present in the peritumoral stroma and quantify their participation in peritumoral inflammatory reaction.  Materials and Methods The study was conducted on a total of 23 stage III (TNM) colorectal adenocarcinomas, operated during 2014 in the II nd General Surgery Clinic of Emergency County Hospital of Craiova, Romania. Immediately after surgery, tumor fragments of about 2/1.5 cm were retrieved from R J M E Romanian Journal of Morphology & Embryology http://www.rjme.ro/