Spinal cord compression by ligamentum flavum hematoma in the thoracic spine.

STUDY DESIGN Case report. OBJECTIVE To report an extremely rare case of hematoma derived from the ligamentum flavum within the thoracic spine. SUMMARY OF BACKGROUND DATA Only one previous case has been reported of a hematoma derived from the ligamentum flavum in the thoracic spine. METHODS.: A 61-year-old man presented with gait disturbance and numbness below the navel. Magnetic resonance imaging on the 16th day after the onset of the symptoms showed spinal cord compression at the T10-T11 level caused by a round mass. This intraspinal, extradural space occupying lesion, continuous with ligamentum flavum was centrally hypointense and marginal hyperintense on a T1-weighted image and central heterogeneous and marginal hypointense on a T2-weighted image. The wall of the lesion was slightly enhanced after use of a contrast medium. RESULTS The patient underwent a T10 laminectomy and the mass was carefully resected from the dura mater. Histologic examination showed that the wall of the mass comprised fibrous connective tissue that contained elastic fibers derived from a degenerative ligamentum flavum tear. It also revealed that evidence of previous hemorrhagic events within the mass. There was no evidence of neoplastic nor synovial tissue. After surgery, the patient's numbness and gait disturbance disappeared. CONCLUSION This report identifies an extremely rare case of spinal cord compression by a hematoma from the ligamentum flavum within the thoracic spine.