ABCL-200 Primary and Secondary Extranodal Diffuse Large B-Cell Lymphoma: A Single-Center Survey from India

Abstract

Approximately 30% of all non-Hodgkin lymphoma (NHL) cases arise from extranodal sites and almost half of them have diffuse large B-cell lymphoma (DLBCL) histology. Not only does the extranodal presentation require a site-specific diagnostic or therapeutic approach, but there is geographical variability in the overall frequency of extranodal presentation as well. To estimate the distribution of sites of extranodal DLBCL in patients treated at a tertiary care center in north India. This retrospective study was conducted at Dr. Bhim Rao Ambedkar Institute Rotary Cancer Hospital, All India Institute of Medical Sciences, New Delhi. Case files of patients (age >18 years) diagnosed with DLBCL at our institute between 2014 and 2018 were retrospectively studied and their sites of disease involvement were surveyed. A total of 550 patients were diagnosed with DLBCL during the study period, including 244 (44.3%) with nodal disease, 224 (40.7%) with extranodal involvement, and 82 (14.9%) with primary extranodal disease. A total of 306 (55.63%) patients have extranodal involvement, either primary or secondary. Among patients with primary extranodal DLBCL (n=82), the most common sites were gastrointestinal (n=36, 43.90%); the stomach was the most common region followed by the central nervous system (n=11, 13.4%), bone (n=8, 9.7%), head and neck area (n=7, 8.5%), breast (n=6, 7.3%), testis (n=4, 4.8%), and liver (n=4, 4.8%). The less commonly involved sites included the spleen (n=2, 2.4%), and one patient (1.2%) each had involvement in the prostate, pancreas, adrenal, and ovary. Bone was the most common site of secondary extranodal involvement observed in 32% of patients followed by gastrointestinal involvement in 30% of cases. Parallel to the incidence of DLBCL, the incidence of extranodal involvement, including primary and secondary extranodal presentation, is high in India. Bone is the most common site for secondary extranodal involvement, and the upper gastrointestinal system (stomach) is the most common site of primary extranodal lymphoma.