Retinoblastoma (RB) is the most common primary intraocular malignancy of childhood. Although current multimodal treatment has considerably improved survival, advanced and recurrent disease still requires enucleation in a substantial proportion of cases and carries long-term psychosocial consequences. RB is driven primarily by biallelic inactivation of the RB1 tumor suppressor gene, together with secondary molecular and epigenetic alterations. A growing body of evidence indicates that RB tumors, particularly poorly differentiated and invasive forms, downregulate HLA Class I expression and antigen-processing machinery, a phenotype that favors escape from cytotoxic T-cell surveillance while creating a biological context that may favor natural killer (NK) cell-mediated recognition through missing-self mechanisms. Preclinical studies consistently show that NK and NK-like effector cells can lyse RB cell lines and enhance antibody-dependent cellular cytotoxicity when combined with anti-GD2 antibodies or chemotherapy, but clinical evidence remains extremely limited, with only a single heterogeneous pilot trial reported to date and no dedicated prospective studies in RB. This review critically synthesizes the biological rationale, preclinical evidence, and clinical/immunogenetic data for NK cell-based immunotherapy in RB and addresses the translational barriers unique to the intraocular environment, including uncertainties in immune cell trafficking across the blood-retinal barrier, delivery-route selection, and cell-manufacturing constraints. We conclude by proposing which RB subgroups, therapeutic platforms, and delivery strategies are most realistic for early clinical development, positioning NK cell-based therapy as a biologically rational adjunct rather than a replacement for current treatment.

Children undergoing hematopoietic stem cell transplantation (HSCT) may require pediatric intensive care unit (PICU) admission; a 2008 meta-regression reported 60% mortality. We estimated contemporary PICU mortality, temporal trends, and mortality risk factors. We searched PubMed, Scopus, and Cochrane Library from 2006 to 2026 for pediatric HSCT studies reporting PICU mortality. Estimates were pooled using a random-effects model, with temporal trends assessed by meta-regression and income-setting subgroup analyses. Of 1555 records, 35 studies including 4553 PICU admissions met inclusion criteria. PICU mortality was 37.35% (95% confidence interval [CI]: 31.54-43.54; I2 = 91.6%): 36.24% (95% CI: 30.30-42.63) in high-income and 41.90% (95% CI: 23.55-63.06) in upper-middle-income countries, without significant difference (p = 0.53). PICU mortality did not correlate with cohort midpoint year (p = 0.23). Invasive mechanical ventilation (odds ratio [OR] 5.02; 95% CI: 2.30-10.99), inotropic/vasopressor support (OR 5.75; 95% CI: 3.12-10.60), and continuous renal replacement therapy (OR 3.94; 95% CI: 2.63-5.92) were associated with mortality (all p < 0.001). Mechanical ventilation remained independently associated with mortality. PICU mortality among pediatric HSCT recipients is lower than the 60% reported in 2008, but remains substantial, particularly with organ support. Data from lower-income settings are scarce, representing a major evidence gap.

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.

Hospital readmission is common after pediatric hematopoietic stem cell transplantation (HSCT), but estimates vary, and associated factors are poorly characterized. We systematically reviewed unplanned readmission after autologous or allogeneic HSCT in pediatric populations and pooled the proportion readmitted within 30 days after discharge from the index HSCT admission. PubMed, Embase, and Scopus were searched for English-language reports published from January 1, 2005, through May 23, 2026. Nineteen reports (nine full-text articles and 10 conference abstracts) were included. Three retrospective single-center cohorts contributed to the primary meta-analysis; 210 of 734 patients were readmitted. The pooled 30-day readmission proportion was 31.7% (95% confidence interval [CI]: 22.6%-42.4%; I[2] = 84.7%). Adding one study of 90-day readmission from transplantation yielded a similar numerical estimate (31.9%; 95% CI: 25.1%-39.4%; I[2] = 78.8%), although the outcome was not equivalent. Fever and infection were the most frequent reasons for readmission. Only one study provided adjusted analyses, and most association results were at high risk of bias. Approximately one in three children was readmitted within 30 days after discharge, but the small, heterogeneous evidence base precludes use of this estimate as a universal quality benchmark.