Pulmonary abscess is a rare but serious condition in pediatric patients, caused by severe pulmonary infection that leads to tissue destruction and necrosis. It can be classified as primary or secondary depending on the cause. Establishing an etiology in pediatric pulmonary abscesses is challenging, underscoring the essential role of advanced imaging techniques, such as computed tomography, in achieving an accurate diagnosis and differentiating among various conditions that may mimic lung abscess. While conservative management with antibiotics is the first line of treatment, some cases may progress and require surgical intervention. We present two clinical cases of pediatric lung abscesses, emphasizing the importance of timely intervention, accompanied by a brief review of current knowledge that highlights key clinical features, diagnostic challenges, and therapeutic approaches in pediatric lung abscess.

Granulomatosis with polyangiitis (GPA), previously described as Wegener's granulomatosis, is a rare autoimmune disease that causes necrotizing systemic vasculitis, affecting small- and medium-sized blood vessels. While adults typically receive GPA diagnoses more frequently, children and adolescents can also experience it, albeit infrequently. In pediatric patients, the disease presents challenges due to its rarity and complex clinical symptoms. Early detection and treatment are essential for minimizing long-term complications and improving outcomes. We conducted a literature review that included cases of GPA in children reported between 2014 and 2024, focusing on their unique clinical presentation and outcomes. In this report, we present a seven-year-old girl characterized by an atypical clinical course that included neurological manifestations, particularly posterior reversible encephalopathy syndrome (PRES) and rapidly progressive glomerulonephritis, resulting in end-stage kidney disease, which required hemodialysis. After analyzing all the data, we found that the patient had been diagnosed with GPA. Clinical symptoms are similar to those reported in the literature. These symptoms include female sex and constitutional symptoms (fever, weight loss, fatigue), arthralgia, and multiple organ involvement (hemoptysis, an image demonstrating pulmonary nodules and peribronchovascular infiltrates), as well as otorhinolaryngological symptoms (including nasal crusting and rhinitis history), along with renal impairment (proteinuria, hematuria, and glomerulonephritis pattern). Our case differs from others in the literature due to its early onset (the average age at diagnosis in the recent research was 12 years old), the patient's poor response to cyclophosphamide (CYC) treatment (she developed right lower and middle lobe pneumonia and hemoptysis), and the unexpected changes in her symptoms. She experienced several paroxysmal events, including confusion, blurred vision, generalized seizures with tonic-clonic movements, and deviation of her eyes to the right side, which was followed by temporary aphasia. These neurological symptoms prompted us to conduct a more thorough investigation, leading us to identify a homozygote mutation C667T in the methylenetetrahydrofolate reductase gene (MTHFR). This case highlights the importance of a high index of suspicion for GPS in patients with constitutional symptoms (fever, weight loss, fatigue), arthralgia, and multiple organ involvement, as well as early detection and timely treatment.

WT1-related disorders comprise a spectrum of conditions resulting from mutations or deletions of the WT1 gene. Alteration in this gene have been associated with many syndromes, including WAGR syndrome, Denys–Drash syndrome (DDS), Frasier syndrome (FS) and Meacham syndrome. We present the case of an 8-year-old phenotypically female child with symptoms of end-stage kidney disease (ESKD), hypertension and anasarca, requiring renal replacement therapy. This case is distinctive due to its unusual onset, the presence of thrombotic microangiopathy (TMA), and the detection of a heterozygous missense mutation in the WT1 gene (c.1298G>A, p.Cys433Tyr) located in exon 8, in association with a 46 XY karyotype. The kidney biopsy indicated advanced focal segmental glomerulosclerosis (FSGS) with characteristics of TMA, implying a possible alternative diagnosis. In light of the heightened malignancy risk, the patient had preventative laparoscopic gonadectomy, which revealed rudimentary testicular tissues. The identified genotype points toward a diagnosis of DDS. However, the clinical presentation is more consistent with features typically seen in FS. This discrepancy highlights the significant phenotypic and genotypic overlap between the two syndromes. As a result, there is ongoing discussion in the literature about whether DDS and FS should be considered distinct clinical entities or rather variable expressions along a shared disease spectrum.

Posterior reversible encephalopathy syndrome (PRES) is a clinical and neuroimaging syndrome that can affect both children and adults and has variable etiology. It is clinically defined by headaches, consciousness disorders, seizures and visual disturbances. Early recognition (clinical and imaging) can lead to appropriate general measures to correct the underlying cause of PRES. In this paper, we report a case of PRES in an eight-year-old boy with bilateral renal hypoplasia and end-stage renal disease (ESRD).

Short QT syndrome (SQTS) is a rare, inherited cardiac channelopathy characterized by an abnormally shortened QT interval, accelerated ventricular repolarization, and an increased risk of atrial and ventricular tachyarrhythmias, including sudden cardiac death (SCD). We report the case of a 14-year-old girl diagnosed with SQTS presenting with persistent atrial fibrillation and a complex independent neurological background. The patient, with no significant family history of cardiac disease or SCD, was incidentally found to have atrial fibrillation and a markedly shortened QT interval during a routine medical evaluation. Although she remained entirely asymptomatic from a cardiovascular perspective, her medical history was notable for maternal Toxoplasma gondii infection during pregnancy, extreme prematurity, and delayed psychomotor development. Electrocardiographic (ECG) findings consistently demonstrated a short QT interval, and genetic testing revealed a likely pathogenic variant in the KCNJ2 gene, consistent with type 3 short QT syndrome (SQTS3). Despite the initiation of antiarrhythmic therapy, atrial fibrillation persisted and the QT interval remained significantly shortened throughout the 24-month follow-up. This case highlights the diagnostic and therapeutic challenges of managing short QT syndrome in pediatric patients, particularly in those who are asymptomatic yet exhibit sustained atrial arrhythmias. It also highlights the coexistence of cardiac channelopathy and neurological comorbidities, emphasizing the importance of a multidisciplinary approach for these distinct clinical entities.