INTRODUCTION: Schwannoma is a relatively common benign spinal cord and/or cauda 
equina tumor; however, giant cauda equina schwannoma with extensive scalloping 
of the lumbar vertebral body is a rare pathology, and the treatment strategy, 
including the use of surgical procedures, is controversial. In this report, we 
present a rare case of a giant lumbar schwannoma of the cauda equina with 
extremely large scalloping of the vertebral body, and we discuss the surgical 
strategy we used to treat this pathology.
CASE PRESENTATION: A 42-year-old Japanese man presented to our department with 
complaints of a gait disturbance and muscle weakness in the left lower limb. His 
muscle strength in the proximal part of the left lower limb was grade 2 or 3/5, 
and he exhibited a mild urinary disturbance on the first visit. X-ray and 
computed tomography myelography of the lumbar spine showed an extremely large 
erosive lesion at the L3 vertebral body. Magnetic resonance imaging of the 
lumbar spine showed a large soft-tissue mass in the spinal canal at L2-L3 and 
the vertebral body at L3. A one-stage complete tumor resection and instrumented 
circumferential fusion were performed via a posterior approach, and a good 
outcome was achieved after the surgery.
CONCLUSIONS: We performed one-stage posterior surgery in a patient with a giant 
cauda equina schwannoma with extensive scalloping of the vertebral body, and a 
good post-operative outcome was achieved.