Malignant peripheral nerve sheath tumor of the femoral nerve: imaging findings and correlation with histopathology

Malignant peripheral nerve sheath tumors (MPNST) are rare and aggressive soft tissue sarcomas. MPNST diagnosis is made based on biopsy, but distinct features are present on ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI). We present a case of a 24-year-old man presenting with abdominal pain and lower-extremity weakness found to have a large MPNST originating from the left femoral nerve and describe findings on imaging and their histopathologic correlation.