Whole-Body MRI in Neurocutaneous Syndromes: Imaging Phenotypes, Surveillance Strategies, and Pitfalls.

Neurocutaneous syndromes associated with peripheral nerve sheath tumors (PNSTs), particularly neurofibromatosis type 1 (NF1) and schwannomatosis (SWN), are characterized by variable tumor burden and multisystem involvement. Whole-body magnetic resonance imaging (WB-MRI) has emerged as an important imaging technique for screening, surveillance, lesion characterization, and treatment monitoring in both pediatric and adult populations. Updated molecular and imaging-based classification systems have further refined characterization of PNST phenotypes. In NF1, WB-MRI enables detection of internal tumor burden, longitudinal assessment of plexiform neurofibromas (PNs), and risk stratification for malignant peripheral nerve sheath tumor (MPNST) development. Diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) mapping improves differentiation between benign and malignant peripheral nerve sheath tumors with emerging data on premalignant precursor lesions called atypical neurofibromatous neoplasms of uncertain biologic potential (ANNUBP). In SWN, evolving diagnostic criteria and genotype-phenotype correlations have increased the importance of imaging in young patients presenting with solitary schwannoma or meningioma. WB-MRI can establish internal tumor burden, define disease extent, and support surveillance strategies across genetically defined SWN subtypes. This review summarizes current applications of WB-MRI in NF1 and SWN, including imaging phenotypes, surveillance strategies, advanced imaging biomarkers, treatment response assessment, and common technical and interpretive pitfalls.