Childhood B-Cell Acute Lymphoblastic Leukemia Following SARS CoV-2 Infection: A Potential Second "Hit" in Leukemogenesis

The Impact of COVID-19 on Pediatric Malignancy Diagnosis and Treatment: Never the Same but Lessons Learned

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic affected the pediatric oncology population globally. Over the course of 2 years, increasing reports have been made to better understand this entity and its pathologic complications on these patients. The pandemic has allowed healthcare providers, hospital systems, and leading oncologic societies to quickly adapt and formulate new guidelines for the effective understanding, management, and treatment of patients with pediatric malignancy.

Difficult acute lymphoblastic leukaemia diagnosis in a paediatric patient with mixed presentation of COVID-19 acute respiratory failure and multisystemic inflammatory syndrome

New diagnoses of leukaemia and other malignancies are recently being made in paediatric patients with COVID-19. The rates of mortality and morbidity in some of these children are expected to be higher. In new cases, concurrent diagnosis can be difficult because multisystemic inflammatory syndrome (MIS-C) and malignancies have similar clinical presentations. We present the case of a preteenage child where the diagnosis of leukaemia was complicated and delayed by a multisystem involvement and an inconclusive bone marrow study. Clinical teams managing children with COVID-19 and MIS-C should suspect leukaemia and other malignancies when the clinical course is complicated and bone marrow suppression is persistent. Prompt diagnosis will allow start of treatment on time, minimising complications.

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.

Leukaemia and lockdown: The delayed infection model of childhood acute lymphoblastic leukaemia and the COVID-19 pandemic

Acute lymphoblastic leukaemia (ALL) is the most common type of leukaemia diagnosed in children. The prevailing hypothesis regarding pathogenesis of childhood ALL was developed by Greaves, and states that ALL is caused by an abnormal immune response to a common infection. The response arises either due to naivety of the immune system caused by a lack of common childhood infections, or genetic susceptibility due to specific alleles. The former explanation is known as the delayed infection hypothesis. COVID-19 is a new infection that no children in the UK were exposed to prior to 2020. Furthermore, the lockdown measures designed to prevent spread of this virus have also greatly reduced spread of other common infections. It is therefore important to examine the evidence for this hypothesis, and to consider it in the context of the pandemic to determine what effect lockdown measures may have on incidence of ALL in children.