Lorlatinib‐Containing Therapy for MYCN ‐Amplified, ALK ‐Mutated Neuroblastoma With Bulky Leptomeningeal Relapse: A Case Report

Central nervous system (CNS) relapse of neuroblastoma carries a poor prognosis, and craniospinal irradiation (CSI) poses substantial long-term toxicity in young children. We report a toddler with MYCN-amplified neuroblastoma harboring somatic ALK R1275Q who developed extensive leptomeningeal relapse with paraplegia. Lorlatinib-containing chemotherapy resulted in near-complete resolution of leptomeningeal disease and full neurologic recovery. Although subsequent CNS recurrence was confirmed and ultimately prompted CSI, the initial response permitted its deferral for 11 months. This case highlights the potential of lorlatinib-containing therapy to reduce CNS tumor burden and serve as a bridging strategy to CSI despite concurrent MYCN amplification.