Abstract
The prevalence of back pain during childhood is 50%; in 22% of these cases, a specific diagnosis can be found. Osteoid osteoma is a rare benign tumor that occursonly in 20% of cases and involves the spine. The aim of this report is to explain an atypical case of lumbar osteoid osteoma with significant neurologic deficit at a very young age. A five-year-old boy was presented with refractory pain in the low back and left extremity for approximately one year. Positive clinical findings were antalgic gait, stiff lumbar spine, weak left big toe extension force and a positive straight leg rising test on the left side. Paraclinical studies revealed osteoid osteoma in the left-sided pedicle of the fifth lumbar vertebra. With surgical excision, he recovered immediately. Lumbar osteoid osteoma should be suspected as the cause of low back pain or sciatalgia in any young patient.