Primary Extranodal Non-Hodgkin’s Lymphoma: An Observational Study at a Tertiary Care Teaching Centre in Northern India

Introduction: Extranodal Non-Hodgkin’s Lymphoma (NHL) constitutes approximately one fourth of all NHL. The data regarding extranodal NHL from India is however limited. Aim: To evaluate the epidemiological and histomorphological patterns of extranodal NHL in a tertiary care institute in Northern India. Materials and Methods: The retrospective observational study was conducted on data of biopsy sections retrieved from the archives for a period of four years (January 2016 to December 2019), 130 extranodal NHL cases (90 males, 40 females) that were analysed for histological features and immunohistochemical subtype. All statistical analysis was done by Statistical Package for Social Sciences (SPSS) software. The values were represented in number, percentage, mean and ratio. Results: Total of 362 cases of NHL were reported. Out of which, 130 (36%) cases were of extranodal NHL. Male to female ratio being was 2.25:1. Mean age of presentation was 38.5 years. Paediatric cases constituted (32/130; 24.6%) cases. Head and neck was the most common site (52/130; 40%) followed by Gastrointestinal Tract (GIT) (21/130; 16.2%) and central nervous system (13/130; 10%). Amongst the paediatric cases, head and neck (11/32; 34.4%) was the most common site, followed by GIT (8/32; 25%). Amongst head and neck lymphomas, nasal cavity and Waldeyer Ring were the most common sites followed by orbit and oral cavity. Common sites among the GIT lymphomas were stomach, small intestine and large intestine. The B-cell NHL constituted 81/130 (62.3%), T-cell NHL 20/130 (15.4%) and NHL (Unclassified) were 29/130 (22.3%). Amongst B-cell type NHL, Diffuse Large B Cell Lymphoma (DLBCL) was the most common subtype. Conclusion: Extranodal NHL diagnosis is challenging due to morphological similarities with non haematopoietic tumours. Lineage determination by Immunohistochemistry (IHC) serves as the key to diagnosis. In our population, head and neck was the most common site, with B-cell NHL being the most common subtype.