Objective and importance: Intraosseous schwannomas (neurilemomas) are rare neoplasms. In one large series, schwannomas accounted for less than 0.2% of all primary bone tumors. These schwannomas most commonly arise in the mandible and have also been observed, very rarely, in the vertebra. We present a patient with an unusual intraosseous schwannoma in the lumbar vertebra.
Clinical presentation: A 58-year-old man who was admitted to Cathay General Hospital had complained of numbness and pain in his lower extremities for approximately 1 year. At the time of admission, a neurological examination revealed mild motor weakness and sensory numbness bilaterally in his lower legs. Magnetic resonance images showed a neoplastic lesion occupying the entire L4 body and the superior part of the L5 body, with marked perivertebral protrusion and compression of the thecal sac and bilateral neuroforamina.
Intervention: The patient underwent a computed tomography-guided needle biopsy and a two-stage operation. During the initial surgical procedure, the tumor mass was totally removed via an anterolateral approach. Fixation and fusion of the third to fifth lumbar vertebral bodies was accomplished using a full-thickness iliac bone graft with an anterior locking plate and screws. During the second operation, posterior fusion of L2, L3, L4, L5, and S1 with Luque wires and a Hartshill rectangle rod was performed to increase the spinal stability.
Conclusion: Intraosseous schwannomas are rare neoplasms that are not commonly observed in the lumbar vertebral bodies. Schwannomas in the lumbar spine commonly originate from the nerve passing through the neural foramina. We report a rare case of L4 intraosseous schwannoma, the magnetic resonance imaging, computed tomographic, and histological findings, and the surgical procedures.