We experiensed 3 cases of giant neurofibromas which grew initially outside the spinal canal and invaded inside thereafter. Cases 1 and 2 were plexiform neurofibroma associated with neurofibromatosis and Case 3 was solitary neurofibroma. All three cases had no neurological deficits. Case 1 was found accidentally by radiological examination of the chest. A biopsy was done. No further treatment was done because of a lack of symptoms. Case 2 visited our clinic with lower back pains and destruction of the right sacroiliac joint was found. Partial resection of the tumor was performed because the tumor had invaded the plexus and the surrounding tissues. At present, 2 years after surgery, she is wearing a brace and has no problems in her daily routines. In case 3, there was a huge neurofibroma on the right side of the 10th thoracic spine, the lamina of which had been destructed by the tumor. The tumor was encapsulated and a radical resection was performed. Although, all three cases showed invasions of a neurofbroma in the spinal canal, the prognoses of cases 1 and 2 were different from case 3 because even though a neurologicl deficit did not occur initially and the nature of the tumor was less agressive, spinal cord damage might occur in the future requiring reconstruction of the bony structure.
