Vascular groove sign in osteoid osteoma of the vertebral body

Osteoid osteoma is a small, benign, painful tumor. Its size is the main distinguishing feature between osteoid osteoma and osteoblastoma and varies between 1.5 and 2 cm. Computed tomography (CT) is usually the best technique for imaging osteoid osteoma because the tomographic nature of the images makes it easy to visualize a lucent nidus, among the surrounding dense bone sclerosis. Vascular supply of osteoid osteoma tumor and nidus are well described. A new CT finding that is vascular groove sign is highly sensitive and specific for osteoid osteoma. It was found that most of this sign was seen in the long bones with very few in the flat bones and only one case of vascular groove sign in the body of the vertebra. A 15-year-old girl presented to us with complaints of lower back pain of 15 months; Pain was a dull-aching type which subsides by nonsteroidal anti-inflammatory drugs and reappears in the middle of the night. She was evaluated and diagnosed to have osteoid osteoma on CT scan with typical vascular groove sign in the vertebral body of L5, which is not mentioned in the literature to the best of our knowledge. Vascular groove sign is highly sensitive and specific for the diagnosis of osteoid osteoma by CT scan; this sign is mentioned mostly in the long bones with only one case in the lamina of the vertebra. We report a case with vascular grove sign in osteoid osteoma of the vertebral body of L5.