Clinical Features and Treatment Outcome of Pediatric Lymphoblastic Lymphoma at South Egypt Cancer Institute

Background: Lymphoblastic lymphoma (LBL) and acute lymphoblastic 
leukemia (ALL) are distinct malignancies arising from immature B or T-cell 
precursors, classified by the World Health Organization. Differentiating them 
relies on blast cell percentages in bone marrow, often 20-25%. LBL treatment 
strategies have shifted from high-grade NHL protocols to ALL-based 
approaches. The study aimed to present the clinical characteristics, overall 
survival (OS), event-free survival (EFS), and common chemotherapy-related 
toxicities observed in patients diagnosed with lymphoblastic lymphoma (LBL) 
over an 8-year period, spanning from January 1st, 2014, to December 31st, 2020.
Methods: A retrospective cohort analysis was conducted on a cohort of 29 
patients diagnosed with LBL and treated using a modified St. Jude TXIII-B 
high-risk protocol.
Results: The cohort had a mean age of 6.21 ± 3.08 years, with 16 patients 
(55.2%) being males and 13 patients (44.8%) females. Primary symptoms 
included difficulty in breathing (51.7%), weight loss (44.8%), peripheral lymph 
node enlargement (31.0%), fever (31.0%), and pallor (17.2%). All patients 
presented with advanced-stage disease, with 82.8% at stage III and 17.2% at 
stage IV. Imaging studies revealed nodal involvement in 31% and extra-nodal 
involvement in 69% of patients. Hemoglobin levels were ≥ 8 g/dL in 82.8%, 
kidney function was normal in 72.4%, and 58.6% had LDH levels ≥ 500 U/L. 
Albumin levels were ≥ 30 mg/dL in 96.6%. Immunophenotyping confirmed T-
cell origin (CD3 positive, CD20 negative) in all patients. Bone marrow 
involvement was observed in 17.2%, and cerebrospinal fluid involvement in 
3.4%. Complete remission was achieved in 75.9% of patients, while relapse 
occurred in 17.2%. Seven patients (24.1%) died, with relapse and severe 
infection being major contributors. Treatment-related toxicities included 
myelosuppression (86%), mucositis (62%), and hepatotoxicity (62%). The 4-
year OS and EFS were 85 ± 7.5%and 78.6 ±3.4% respectively.
Conclusion: The study's findings align with similar research on LBL treatment. 
Patients with relapse had poor outcomes, emphasizing the need to identify 
prognostic factors like minimal residual tumors for better chemotherapy 
response evaluation. The study also noted specific chemotherapy-related side 
effects, calling for careful treatment planning and management strategies.