A misdiagnosed case of osteoid osteoma of L5.

Clinically, it is difficult to differentiate osteoid osteoma, more than 50% of which occur in the fibia or tibia, from other diseases, i.e. spinal degenerative diseases, inflammatory and noninflammatory arthritis. In this case report, we presented an unusual case of lumbar osteoid osteoma in a 38-year-old male, who experienced low back pain and sciatica as initial symptoms. The patient was initially misdiagnosed as lumbar disc herniation for more than 10 years. With the usage of computed tomography (CT) and magnetic resonance imaging (MRI), the patient was finally diagnosed as osteoid osteoma in L5. To our knowledge, spinal osteoid osteoma with sciatica as initial symptoms has never been reported. Although lumbar vertebra osteoid osteoma is clinically uncommon, it should be taken into consideration especially when patients experience long duration of pain in lumbar.