AIM: Cancers that metastasize to the cauda equina are uncommon. Only seventeen cases were reported. Those from pulmonary squamous cell carcinoma was never been published to our knowledge.

MATERIAL and METHODS: A 79-year-old male patient presented with low back pain since 1 year and severe sacral pain irradiating to the left leg, paraparesis, urinary dysfunction and leg weakness since one week.

RESULTS: Preoperative magnetic resonance images of the lumbar spine showed an intradural spinal mass in L2-3 with infiltration of the cauda equina; the lesion measured 13 mm craniocaudally and 11 mm anteroposteriorly, and thus occupied the majority of the intrathecal space at that level. The magnetic resonance images, surgical treatment, and related pathophysiology are reviewed.

CONCLUSION: The majority of cauda equina tumors are primary tumors, and metastases are very rare. Especially old patients with intradural mass and rapidly progressive cauda equina syndrome should be evaluated for a primary malignancy to avoid an unnecessary spinal operation.