Abstract
Lymphoblastic lymphoma (LBL) is a rare, aggressive malignancy comprising T-cell (T-LBL) and B-cell (B-LBL) subtypes. While outcomes for LBL have improved, comprehensive national data on clinical and biological features remain limited. We conducted a retrospective review of children and adolescents with LBL in Ireland over 20 years (2004-2023). Data on demographics, clinical presentation, tumour characterization, treatment protocols, and outcomes were analysed. The cohort included 52 patients: 79% with T-LBL and 21% with B-LBL. T-LBL cases predominantly affected males (2.2:1) and presented with advanced disease, including mediastinal masses (98%) and high lactate dehydrogenase levels. B-LBL cases had a female predominance (0.4:1) and localized disease (82%). Survival outcomes were excellent for B-LBL, with 5-year event-free survival (EFS) and overall survival (OS) of 100%. For T-LBL, 5-year EFS and OS were 85%. Relapsed/refractory disease occurred in 4% (T-LBL only). Genetic, Minimal Disseminated Disease and Minimal Residual Disease analyses were limited. LBL outcomes in Ireland align with international reports, highlighting favourable survival but underscoring the need for improved risk stratification and genetic profiling, particularly for T-LBL.