Pleuropulmonary blastoma (PPB) is a tumor occurring almost exclusively in infants and young children. This is the most common primary-lung malignancy in childhood. There is age-associated progression through a distinctive sequence of pathologic changes, from a purely multicystic lesion type I to a high-grade sarcoma type II and III. While complete resection is the cornerstone treatment for type I PPB, aggressive chemotherapy with a less favorable prognosis is associated with type II and III. DICER1 germline mutation is positive in 70% of children with PPB. Diagnosis is challenging, as it resembles congenital pulmonary airway malformation (CPAM) in imaging. Although PPB is an extremely rare malignancy, over the past five years we have encountered several children diagnosed with PPB in our medical center. Herein, we present some of these children and discuss diagnostic, ethical, and therapeutic challenges.

Purpose The second year of life is gaining increased attention in the era of long-acting RSV immunoprophylaxis. This multicenter study, across pre- and post-COVID seasons, aimed to assess the association between specific key risk-factors and severe RSV-related disease among hospitalized children aged 12–23 months. Methods This retrospective study included children aged 12–23 months hospitalized with RSV across 11 medical-centers (2017–2021). We compared outcomes of prolonged hospitalization (> 3 days) and PICU (Pediatric Intensive Care Unit) admission for children with risk factors (prematurity < 37 weeks, major congenital heart disease (CHD), chronic lung disease of prematurity (CLD) or Down syndrome (DS)) and those without the respective risk factor, adjusting for demographic variables and COVID-19 pandemic admission. Clinical outcomes were also compared between children with ≥ 1 risk factors and those with none. Results Among 1023 children, 228 (22%) had ≥ 1 risk factor: prematurity (n = 183), CLD (n = 28), CHD (n = 45) or DS (n = 20). In multivariable analysis, prematurity with CLD (aOR 4.7,95%CI:1.97–11.22) or without CLD (aOR 2.26, 95%CI:1.54–3.3), CHD (aOR-3.29, 95%CI:1.6–6.77), DS (aOR-4.14, 95%CI:1.26–13.6) and having ≥ 1 risk (aOR-3.55, 95%CI:2.55–4.96) were independently associated with prolonged hospitalization. DS (aOR 6.7, 95%CI:2.1–22.4), CHD (aOR 3.0,95%CI:1.04–8.66) and having ≥ 1 risk factor (aOR-3.58, 95%CI:1.89–6.80) were also associated with PICU admission. Conclusion Children aged 12–23 months with prematurity, CLD, major CHD or DS had significantly higher rates of prolonged RSV hospitalization. Those with ≥ 1 risk factor, and presumably patients with DS and CHD are at highest risk for severe complications. Preventive strategies for these high-risk populations should be considered in their second-year of life. What is Known: • Children with prematurity, congenital heart disease (CHD), chronic lung disease of prematurity (CLD) or Down syndrome (DS) are at increased risk for severe RSV-related illness in the first year of life. • The second year of life is now relevant for long-acting RSV prevention strategies. What is New: • This multicenter study shows that prematurity, CLD, CHD, and DS remain strong predictors of prolonged RSV hospitalization in children aged 12–23 months. • Those with ≥ 1 risk factor, and presumably those with DS and major CHD, faced the highest risk, with increased likelihood of PICU admission.