Clinicopathological Profile of Primary Extra Nodal Lymphoma from a Tertiary Care Center in South India

Background & Objective: Primary extranodal lymphoma (pENL) is a malignant lymphoid neoplasm that presents with the main bulk of disease at an extranodal site. The incidence of primary pENL has risen sharply in recent years due to the advent of better diagnostic modalities. Diagnosing pENL can be challenging due to its morphological overlap with other tumors native to the site of origin. This study aims to establish the anatomic distribution, clinical presentations, possible etiologic correlations, and histological subtypes of pENL in a tertiary care center located in South India. Methods: This is a retrospective study of 109 patients with pENL (69 males, 40 females, M: F = 1.7:1) over 5 years (October 2012 to September 2017). The tumors were reclassified according to WHO classification of Haematolymphoid tumors, 5th edition, 2022. Results: pENL constituted 109/481 cases (22.6%) of all NHL cases, with the highest incidence in 7th decade. The gastrointestinal tract (39%) was the predominant site involved, followed by head and neck (26%). Diffuse large B cell lymphoma (DLBCL) was the most common histomorphological variant followed by Follicular lymphoma (FL). The majority of the patients were immunocompetent (89%) and presented with stage IV disease (31.1%) at diagnosis. Conclusion: This study presents an overview of the diverse distribution patterns of both common and rare pENL within a tertiary care center. The accurate diagnosis of pENL necessitates the elimination of secondary extranodal involvement. It is important to note that the accurate diagnosis of pENL requires careful evaluation and exclusion of other possible causes.