Sardar, GSBandyopadhyay, GChowdhury, ARTalukdar, M.2023-06-272023-06-272022-05Sardar GS, Bandyopadhyay G, Chowdhury AR, Talukdar M.. Study of extra-nodal lymphoma with special reference to histomorphology, immunohistochemistry, and topographical distribution. National Journal of Physiology, Pharmacy and Pharmacology. 2022 May; 12(5): 560-5632231-32062320-4672http://imsear.searo.who.int/handle/123456789/217571Background: Primary extra-nodal lymphomas (ENLs) are rare neoplasm but can affect many organ systems of body. Proper and timely diagnosis and justified treatment of primary ENL are often affected due to variety of lymphoma types and the relative rarity of many of these tumor types. They are mainly of Non-Hodgkin lymphoma which further consists of many subtypes having variation of epidemiology and clinical presentation along with geographic distribution. Aim and Objectives: Aim and objectives of the study were to find out topographical distribution and histological patterns of ENL along with their immunohistochemical character in a tertiary care hospital of Eastern India. Materials and Methods: All the cases from April 2015 to March 2018 diagnosed as ENL by histopathological examination were included in this descriptive cross-sectional study for further immunohistochemical analysis for CD45 Life-cycle assessment (LCA), CD3 and CD 20 to identify the cell of origin (B cell vs. T cell). Results: Out of total 31 cases, 67.74% were male and the most common age group was 51–60 years. Gastrointestinal tract was the most common organ system (61.29% of cases) affected and stomach (29.03%) followed by Ileum (9.67%) were the most common sites affected by ENL. Histomorphologically diffuse large cell lymphoma was the most common pattern while immunohistochemistry study revealed all the cases were B cell type with LCA and CD 20 positive and CD3 negative. Conclusion: This study revealed the topographical pattern along with predominant histomorphological and immunohistochemical character of ENL in study population. However, further studies with meta- analysis can enlighten these characters more comprehensively.ImmunohistochemistryExtra-nodal LymphomaHistomorphologyJournal ArticleIndiaDepartment of Blood Bank, North 24 Parganas District Hospital, Barasat, West Bengal, IndiaDepartment of Pathology, Burdwan Medical College, Burdwan, West Bengal, IndiaDepartment of Pathology, Murshidabad Medical College, Berhampore, West Bengal, IndiaDepartment of Pathology, Medical College and Hospital, Kolkata, West Bengal, India