Posterior Reversible Encephalopathy Syndrome (PRES) is a rare but potentially reversible neurological manifestation associated with Multisystem Inflammatory Syndrome in Children (MIS-C). We report an eight-year-old boy who developed PRES secondary to MIS-C following asymptomatic SARS-CoV-2 exposure. The patient presented with fever, seizures, decreased consciousness, and visual disturbances. MRI revealed characteristic bilateral parieto-occipital and posterior temporal cortical–subcortical hyperintensities, while CT scans were normal. The patient achieved full neurological recovery with corticosteroid therapy, blood pressure control, and supportive management. This case underscores the importance of early MRI in detecting PRES when clinical or CT findings are inconclusive, emphasizing the need for heightened awareness among pediatric clinicians to prevent irreversible neurological sequelae.

Background: PIK3CA-related overgrowth spectrum (PROS) comprises a heterogeneous group of mosaic disorders characterized by segmental overgrowth and vascular anomalies. Although genetic confirmation is considered the diagnostic gold standard, it is often limited by mosaicism and availability, necessitating integration of clinical examination, imaging findings, and molecular testing when available for accurate diagnosis and phenotypic classification. Case presentation: We present two pediatric cases representing distinct phenotypes within the PROS continuum. The first case demonstrated congenital unilateral enlargement of the left upper extremity, with MRI revealing predominant subcutaneous adipose hypertrophy without evidence of vascular malformation, consistent with fibroadipose overgrowth (FAO). The second case was identified prenatally on fetal MRI as a large, multiloculated cystic lesion involving the retroperitoneum, abdominal wall, pelvis, and left lower extremity. Postnatal imaging confirmed a complex, trans-spatial slow-flow veno-lymphatic malformation with associated adipose overgrowth, most consistent with the CLOVES phenotype within the PIK3CA-related overgrowth spectrum. Longitudinal imaging guided both diagnosis and management. Discussion: Imaging plays a central role in differentiating PROS entities based on dominant tissue characteristics and vascular dynamics. FAO is defined by adipose-predominant overgrowth without a vascular nidus, whereas CLOVES syndrome demonstrates extensive slow-flow vascular malformations with multi-compartment involvement. Notably, both cases exhibited left-sided predominance, consistent with reported PROS patterns. Conclusion: Radiologic phenotyping enables accurate classification within the PROS spectrum and guides management, even in the absence of genetic confirmation.

Background: This study aims to characterise the clinical and radiological features of Posterior reversible encephalopathy syndrome (PRES) in the context of multisystem inflammatory syndrome in children (MIS-C), consolidating reported cases to aid clinicians in diagnosis, management, and future research. Methods: A systematic review was conducted, adhering to PRISMA guidelines and registered under PROSPERO (CRD420251011869). Four academic databases and grey literature sources were searched up to April 2025. Inclusion criteria were cases with confirmed MIS-C and a diagnosis of PRES supported by compatible clinical and radiological findings or reported by the original investigators when detailed imaging information was unavailable. Results: Sixteen studies encompassing sixteen pediatric cases were identified. The majority were female, with a median age of 9 years. Among patients with available data, hypertension was reported in 8 cases, seizures in 9 cases, and visual disturbances in 4 cases. MRI findings predominantly showed cortical-subcortical hyperintensities in the parieto-occipital, posterior temporal, and frontal lobes. CT was frequently normal. Radiological regression was observed in most follow-up MRIs. Reported management was heterogeneous and variably described, including treatment of hypertension and seizures when present, alongside treatment of MIS-C and other potential precipitating conditions. Favourable clinical outcomes were reported in the published cases in which outcome information was available, with a median length of hospital stay of 26 days (range: 8–45 days). PRES is a rare but clinically important neurological condition reported in children with MIS-C. MRI remains the imaging modality of choice due to its sensitivity in detecting characteristic vasogenic edema, which is often missed on CT. Conclusions: PRES has been reported in a small number of children with MIS-C, but the available evidence is heterogeneous and subject to substantial diagnostic, selection, and publication biases. The relationship between MIS-C and PRES and the prognosis of affected patients still remain to be further elucidated.