Malignant peripheral nerve sheath tumor in the paraspinal region mimicking a benign peripheral nerve sheath tumor: a case report

Malignant peripheral nerve sheath tumors are extremely rare in the general population and display a predilection for metastasis to the lungs. Here, we present a rare case of a malignant peripheral nerve sheath tumor located in the paraspinal region and highlight the importance of preoperative biopsy in diagnosis of spinal epidural peripheral nerve sheath tumors.

We describe the clinical course of the patient as well as the radiological and pathological findings of the tumor.

A 14-year-old girl presented with a six-month history of sacral pain. Occasionally she experienced left leg pain and abnormal gait. General physical examination revealed sensorial loss in the L5–S1 regions. T1-weighted sagittal MRI showed a hypointense oval mass and the contrast-enhanced T1-weighted axial MRI image showed heterogeneous enhancement of the tumor. On CT imaging, this tumor characteristically appears as a dumbbell-like mass with punctate calcification and widening L5–S1 intervertebral foramen. Complete resection was performed using an anterior approach. Intraoperative pathological examination revealed evidence of malignancy and subsequent immunohistochemical analysis of the tumor confirmed the diagnosis of MPNST. The postoperative course was uneventful and the patient has had significant improvement in her symptoms 1 month postoperatively.

Preoperative biopsy should be routinely performed for pathological differential diagnosis of spinal epidural PNSTs as well as surgical decision-making. Furthermore a combination of clinical manifestation, radiological findings and biopsy should also be pursued for diagnosing these tumors.