Int J Cancer Manag. 2021 June; 14(6):e97892. Published online 2021 July 5. doi: 10.5812/ijcm.97892. Research Article Multicentric Study of Clinicopathological Features of Primary Gastrointestinal Lymphoma of Iran: from 2011 - 2016 Farahnaz Bidarizerehpoosh 1 , Samira Ghasemi 1 , Arsham Moradi 2 , Afshin Moradi 3 , Behrang Kazeminezhad 1 , Elena Jamali 4 , Tahmineh Mollasharifi 1 , Kamran Ghaffarzadehgan 5 , Arash Dehghan 6 , Abolfazl Movafagh 7 , Amir Sadeghi 8 , Mahsa Ahadi 1 , Sara Zahedifard 5 and Malihe Saberafsharian 9, 10, * 1 Department of Pathology, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2 Department of Biology, University of Toronto, Toronto, Canada 3 Cancer Research Center, School of Medicine, Shohada Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran 4 Department of Pathology, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran 5 Cancer Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran 6 Pathology Department, Hamedan University of Medical Sciences, Hamedan, Iran 7 Department of Genetic, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran 8 Research Center for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran 9 Azad Medical University, Mashhad, Iran 10 Men’s Health and Reproductive Health Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran * Corresponding author: Men’s Health and Reproductive Health Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Email: saberafsharian@yahoo.com Received 2020 September 12; Revised 2021 February 16; Accepted 2021 May 03. Abstract Background: Gastrointestinal (GI) tract is the most common site for extranodal lymphoma. The primary GI lymphoma pattern in Iran is different from western countries and has been changed during the past 40 years. Objectives: This study was done to determine the clinical and pathological characteristics of primary GI lymphoma in Tehran, Hamedan, and Mashhad regions in Iran. Methods: In this cross-sectional comparative-descriptive study, 200 patients with primary GI lymphoma in Tehran, Hamadan, and Mashhad regions from 2011 to 2016 were enrolled in a consecutive manner, where the clinical and pathological characteristics of cases were determined. Results: Among 200 patients, 141 (70.5%) subjects were male and 59 (29.5%) subjects were female. The mean age at diagnosis was 54.3 ± 19.3 years. Also, 84%, 8.5%, and 7.5% of the patients’ specimens were from Tehran, Hamedan, and Mashhad, respectively. The stomach was the principal involved location in approximately half of the cases. Diffuse large B-cell lymphoma (DLBCL), was the main subtype that was observed in 64% of the cases. Treatment in 72% of cases was a combination of surgery and chemotherapy. The 5-year survival was assessed in 147 patients with a rate of 68%. Conclusions: Primary GI lymphoma is seen more in male subjects younger than 60 years of age with non-specific symptoms. Also, DLBCL and MALToma are the main histologic types, and the 5-year survival for all cases is 68.0%. The clinical symptoms showed no specific pattern and accordingly, patients with weight loss and abdominal pain should be considered in in differential diagnosis of malignant lymphoma. Keywords: Lymphoma, Non-Hodgkin Lymphoma, Gastrointestinal, Extranodal, Iran 1. Background Lymphoid neoplasms are one of the most common ma- lignancies worldwide (1). Gastrointestinal (GI) tract is the most common site for extranodal lymphoma with a rate between 4% and 20% of all NHL cases (2-6). Primary GI lym- phoma is rare and accounts for 1% to 4% of all GI malig- nancies (1-3) especially in elderly male subjects (7). The dis- tribution and the prognosis in various regions are differ- ent, and better prognosis is expected in Europe and the United States due to earlier diagnosis and better treatment (1) that is not feasible in Asian and developing countries. In the GI part, stomach is the most commonly involved site and thereafter the ileocecal, small intestine, pharynx, colon, and occasionally the esophagus are affected (3-5). Di- agnosis should be made according to the Dawson’s criteria that include (1) absence of peripheral lymphadenopathy at Copyright © 2021, Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.