Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 52 10 2014 10 15 791 794 EN Jalall Vahedian Ardakani Department of Surgery, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran. Nikdokht Rashidian Department of Surgery, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran. Amir Ashkan Adman Department of Surgery, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran. Mohammad Reza Keramati Department of Surgery, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran. 2015 10 11 Colorectal lymphoma is an extremely rare disease, representing less than 0.5% of all primary colorectal neoplasms. The disease is usually diagnosed in the advanced stages because of its primary non-specific symptoms. The most common involved site is cecum followed by rectum and ascending colon. Diffuse large B-cell lymphoma is a more frequent subtype. Although surgical resection is often technically feasible, optimal therapy for a colorectal lymphoma, especially rectal lymphoma, has not yet been identified. The authors describe a patient with the primary rectal lymphoma, high-grade features and complete response to chemotherapy. https://acta.tums.ac.ir/index.php/acta/article/view/4545 https://acta.tums.ac.ir/index.php/acta/article/download/4545/4651