Isolated CNS Relapse in 2 High-Risk B-cell Acute Lymphoblastic Leukemia Patients Following SARS-CoV-2 Infection.

B-cell acute lymphoblastic leukemia (B-ALL) is the most common pediatric malignancy with a highly favorable overall prognosis. Central nervous system (CNS) relapse of B-ALL is relatively rare and is associated with inferior survival outcomes. We present two patients with B-ALL who developed isolated CNS relapse following confirmed infection with severe acute respiratory syndrome coronavirus 2. In addition to individual and disease factors, we posit that delays in therapy together with immune system modulation because of severe acute respiratory syndrome coronavirus 2 may account for these 2 cases of CNS relapsed B-ALL. We report on this clinical observation to raise awareness of this potential association.