Malignant peripheral nerve sheath tumors arising in SMARCB1-associated schwannomatosis: illustrative cases

These cases emphasize clinical vigilance for malignant transformation in schwannomatosis, particularly with rapidly enlarging lesions or new neurological symptoms. MRI and FDG-PET can aid in identifying concerning features. Despite margin-negative resection, recurrence and metastasis may occur, reflecting the tumor's aggressive biology. Genetic counseling may be considered in SMARCB1-associated cases. While malignant transformation is much more common in NF1 lesions, rare cases do arise in schwannomatosis, requiring close surveillance and multidisciplinary management. https://thejns.org/doi/10.3171/CASE25610.