TCL-628: Prevalence of T-cell lymphomas at the All India Institute of Medical Sciences (AIIMS), New Delhi, India

Abstract

Context: T-cell lymphomas (TCL) constitute a heterogeneous category of non-Hodgkin lymphomas (NHL) originating from T lymphocytes and natural killer (NK) cells. They constitute roughly 5% to 10% of all lymphomas inWestern regions and 15% to 20% in East Asia. Objective: Adequate data concerning the occurrence and distribution of the T-cell non-Hodgkin lymphoma (T-NHL) subtype are insufficient from India, as indicated by the WHO 2016 classification. Setting, Design, and Participants: This is a retrospective analysis of newly diagnosed patients with NHL treated in the Department of Medical Oncology at AIIMS, New Delhi. Over the course of a decade (2014–2023), a total of 1,800 cases of adult lymphoma (defined as those affecting individuals aged ≥18 years) were recorded. Final tally: 250 cases (14%) of NHL were T-cell–related. The most common subtype of peripheral T-cell lymphoma is PTCL-NOS, which accounts for 90 cases (36%) of the total. Anaplastic large cell lymphoma (ALCL) is the second most common subtype at 24%, followed by extranodal natural killer (NK)/T-cell lymphoma, nasal type (ENKTL/NKTCL) at 29 cases (12%), T-cell lymphoblastic lymphoma at 20 cases (8%), angioimmunoblastic T-cell lymphoma at 10 cases (4%), enteropathy-associated T-cell lymphoma at 2%, follicular T-cell lymphoma/hepatosplenic T-cell at 2%, T prolymphocytic leukemia at 0.8%, and three cases that were undescribed (1%). Approximately 10% of all T-cell lymphomas are cutaneous T-cell lymphomas, which accounts for 25 cases. Mycosis fungoides (MF) was the most common one, which was present in 17 cases (7%); followed by Sezary syndrome at 3 cases; lymphomatoid papulosis at 2 cases; and primary cutaneous anaplastic large cell lymphoma, subcutaneous panniculitis-like T-cell lymphoma, and cutaneous gamma delta T-cell lymphoma at 1 case each, respectively. Conclusion: The most common subtype of PTCL was PTCL-NOS, followed by ALCL and extranodal NK/T-cell. The incidence of T-cell lymphoma in the Indian population is higher than in the Western population and lower than in the East Asian population; potential factors include variations in viral infections (eg, EBV), genetic susceptibility, and environmental impacts.