Unusual Radiographic Presentation of Tuberculous Spondylitis : 3 Cases of Mimic Spinal Metastasis

Background Spinal infection and tumor are common diseases that cause back pain with collapsed vertebrae. Radiographic fi ndings of spinal tuberculosis are similar to those of spinal metastasis. Objective To radiographically demonstrate that spinal tuberculosis is able to mimic spinal metastasis. Patients and methods Three cases were collected during January to June 2008. All presented with nonmechanical back pain with or without neurological defi cit. Plain radiographs, myelography, technetium bone scan, computed tomography (CT) scan and magnetic resonance (MR) imaging of the spine were done. All patients were treated surgically. Tissue specimens were sent for analysis. Results and discussion Study subjects comprised 2 men and 1 woman, with an average age of 51 years. Plain radiographs of two cases showed destruction of the vertebral bodies, pedicles and posterior elements of the spine. Disc spaces and vertebral endplates were preserved. The other case had disc space and endplate destruction, but a CT scan strongly suggested spinal metastasis. All specimens showed chronic caseating granulomatous infl ammation without malignancy. Generally, the radiographic fi ndings suggested spinal metastasis destructive of the vertebral body, but they did not include the vertebral endplates or intervertebral discs. The earliest sign was pedicle erosion. Spinal tuberculosis destroyed the body. It might also spare the disc and the posterior neural arch in early phases. Finally, a biopsy should be done. Conclusion Radiographic presentation of spinal tuberculosis is able to mimic spinal metastasis. Tissue diagnosis before treatment is mandatory. Chiang Mai Medical Journal 2008;47(4):189-199.