Neurofibromatosis type 1 with bladder neurofibroma followed by retroperitoneal malignant peripheral nerve sheath tumor: a case report.

Bladder involvement in neurofibromatosis type 1 is rare. We report a pediatric case of bladder plexiform neurofibroma treated with partial cystectomy, ileal augmentation cystoplasty, and ureteral reimplantation. Although low-pressure urinary tract reconstruction was achieved, the patient did not regain the ability to void spontaneously, requiring long-term suprapubic cystostomy and ureteral stenting. Five years later, the patient developed retroperitoneal malignant peripheral nerve sheath tumor. Despite subtotal resection and pazopanib therapy, the disease progressed and the patient died at 14 years of age. This case highlights persistent functional morbidity and later malignant progression during the long-term course of NF1-associated pelvic disease.