Malignant granular cell tumor mimicking herniated nucleus pulposus

Peripheral nerve tumors may arise in any nerve, large or small. Their presence is readily apparent when they are superficial, but when they are located in a deep nerve, symptoms can mimic+ the nerve root pain of herniated nucleus pulposus. This case of malignant granular cell tumor, probably of Schwann cell origin, involved the sciatic and tibial nerves in the popliteal fossa. Originally the pain was assumed to be produced by a herniated nucleus pulposus. The discovery of the mass thus +was delayed. The mass gave a heterogeneous signal on magnetic resonance imaging studies. A peripheral origin of nerve pain should be considered whenever pain radiates to a limb. A complete physical examination that includes palpation of the nerve to which pain is referred gives the best clue as to the true cause of pain when a peripheral nerve tumor is present.