[A case of pyogenic spondylitis mimicking spinal invasion of lung cancer].

A 65-year-old man who had suffered from traumatic spinal cord injury had chronic lumbar pain. He had exacerbation of lumbar pain and intermittent fever and consulted several doctors, but the cause of the lumbar pain was unknown. An orthopedic specialist took an MRI. Spinal MRI showed increased signal intensity at the level of T10-11 and a mass in his right lower lung field, so he was referred to our hospital. Two transbronchial lung biopsy procedures failed to obtain malignant cells. CT guided biopsy showed fibrous and hyalinizing tissue contained plasma cells and lyphocytes. Staphylococcus aureus was cultured from the second bronchial lavage fluids of brush and blood cultures, so we began administration of ampicillin-sulbactam. Avoiding threatened or actual cord compression due to collapse resulting from spinal instability, posterior fusion with instrumentation was done through the back of his chest wall. At once, bone biopsy was done, and showed no malignant cells. As soon as antibacterial treatment was stopped after the operation, he had bloody sputa and fever. The antibacterial agent was resumed and the symptoms improved. The mass decreased in size and lumbar pain improved gradually, so we concluded the diagnosis was pyogenic spondylitis caused by S. aureus. After about 5 months of antibacterial treatment, the tumor substantially diminished.