MCL-071 Bone marrow involvement and immunohistochemical profile in mantle cell lymphoma—experience from a North Indian Tertiary care center over 10 years

Abstract

Context: A comprehensive analysis of pathological characteristics of mantle cell lymphoma in Indian patients is lacking. Objective: Primary objective was to evaluate bone marrow (BM) involvement and immunohistochemical (IHC) profile in Indian MCL patients. Secondary objective was assessing factors affecting OS and EFS. Design, setting, and study participants Ambispective analysis of clinicopathological data from 91 MCL patients diagnosed and treated between January 2013 and December 2023 at IRCH-AIIMS, New Delhi, India. Outcomes measures: Categorical, continuous variables summarized as frequency (percentage), median (range), respectively. STATA 13.0 assessed factors affecting OS and EFS in univariate and multivariate logistic regression (Cox proportional hazards model; adjusted hazard ratio [aHR], 95% CI). P value <.05 defined statistical significance. Results: Extranodal (EN) or BM involvement (73 cases [80.0%], 52 [57.0%]). Pattern (overlap): interstitial, 32 (62.0%); paratrabecular, 32 (62.0%); diffuse, 15 (29.0%). Gastrointestinal involvement: 18 (20.0%). Splenomegaly: 47 (52.0%). 40.0% (35/88) had atypical cells in peripheral blood (PB) by flow cytometry with simultaneous BM involvement. Fourteen (15.0%) had BM without PB involvement. Leukocytosis (TLC>10,000 cells/m³) in 33 (37.0%), anemia (Hb<10g/dL) in 26 (29.0%). Median LDH 304 U/L (range: 132-983 U/L); LDH ≥ ULN in 23 (25.0%). Histological variants: classical, 67 (75.0%); blastoid, 19 (21.0%); pleomorphic, 4 (4.0%). All cases were CD20+, CD3-. 20.0% (16/79) CD5-, 93.0% (70/75) CD23-. Three of 89 (3.0%) cyclin D1- and SOX11+. CD10, BCL-2, BCL-6 positivity in 2/74 (3.0%), 36/40 (90.0%), 4/48 (8.0%), respectively. Ki-67 ≥30% in 42/60 (70.0%). In univariate analysis, only anemia was significantly associated with poor OS and EFS; no association between EN involvement, LDH ≥ ULN, or pleomorphic/blastoid variants and outcomes. Leukocytosis was associated with poor EFS but not OS. In multivariate analysis, anemia was associated with poor EFS (aHR [95%CI]: 2.02 [1.15-3.55], P =.01). Conclusions: The first comprehensive analysis of pathological characteristics of MCL patients from India showed that over half had BM involvement, the most common being interstitial or paratrabecular pattern. Classical was the most frequent histological variant. One-fifth of cases were CD5- and 3% were cyclin D1-. Anemia was associated with poor OS and EFS in univariate analysis but only poor EFS in multivariate analysis.