Introduction:
Lymphoblastic Lymphoma (LBL) is the second most common Non-Hodgkin
lymphoma (NHL) among children, of which T-Lymphoblastic Lymphoma (T-LBL)
accounts for 75-85% of cases and B-Lymphoblastic Lymphoma accounts
(B-LBL) for the remaining1. B-LBL is morphologically
indistinguishable from B- acute lymphoblastic leukemia (B-ALL) with a
homogenous proliferation of medium-sized cells with high
nuclear-cytoplasmic ratio expressing pan-early-B cell markers, TdT,
HLA-DR with variable expressivity for CD10 and CD342.
Pediatric B-LBL(pB-LBL) usually presents at a younger age (<6
years) with lower stage disease and rare mediastinal and marrow
involvement compared to T-LBL3. With the efforts of
major international co-operative groups, current overall outcomes of
pB-LBL exceed 80%4. However, salvage rates among
relapsed/refractory pB-LBL patients remain poor5.
Further improvement in outcomes of pB-LBL is marred by the overall low
incidence of LBL and the lack of substantial tissue specimens for
biological studies4.
Robust prognostic markers such as cytogenetic translocations and minimal
residual disease (MRD) detection which aid in treatment optimization in
children with B-acute lymphoblastic leukemia (B-ALL) are still lacking
for pB-LBL. Also, morphologic response criteria assessed by
X-rays/CT-Scans are not uniform across various LBL trials, especially
for pB-LBL patients. The role of minimal disseminated disease (MDD)
detection and functional imaging such as FDG-PET/CT in the management of
pB-LBL is still evolving6,7. Ongoing trials in LBL
focus on identifying specific prognostic factors necessitating
escalation of treatment or addition of novel therapies among high-risk
subsets to improve outcome, as well as de-escalation among low-risk
patients to avoid exposure to untoward toxicity. Here we report the
clinical profile and long-term outcomes of pB-LBL patients treated at
our center using a uniform strategy and identified factors that affect
their outcomes.