Inflammatory myofibroblastic tumor in the intradural extramedullary space of the lumbosacral spine: a case report and review of the literature

Inflammatory myofibroblastic tumor (IMT) is a rare, benign lesion of uncertain etiology, predominantly affecting soft tissues such as the lungs, with spinal involvement being exceedingly rare. We present the case of a 10-year-old male with a year-long history of low back pain, constipation, and difficulty in urination. MRI revealed an intradural extramedullary lesion at L5-S1, initially suspected to be a schwannoma or neurofibroma. The patient underwent L5 laminectomy and near-total excision of the tumor. Histopathological examination confirmed IMT, characterized by spindle cells and dense inflammatory infiltration. At 18 months follow-up, MRI showed no tumor progression with complete clinical improvement. This is the first reported case of IMT in pediatric age, affecting the lumbosacral spine. It highlights the importance of considering IMT in the differential diagnosis of spinal tumors, particularly when multiple nerve roots are involved, with intraoperative findings of an inflammatory lesion. Surgery remains the definitive treatment.