Age / Sex : 26 / M

Chief complaint: Posterior neck pain, Left upper extremity pain

What is your diagnosis?

Two weeks later, you can see the final diagonosis with a brief discussion of this case (Please submit only one answer).

Courtesy : Bo Ram Kim and Joon Woo Lee, Seoul National University Bundang Hospital

Discussion

Answer:  osteoid osteoma

Findings:

C -spine radiographs show round bone forming lesion around left C7 superior articular process.

MR images show a subcortical nidus with internal calcification in hypertrophied left C7 superior articular process. The nidus is surrounded by extensive bone marrow edema, reactive sclerosis and soft tissue edema

Differential Diagnosis:  Osteoid osteoma, Osteoblastoma, Intracortical abscess

Discussion:

The most common location of spinal osteoid osteoma is the lumbar segment, followed by the cervical segment and the thoracic segment. In most cases, the nidus is located in the neural arch. Patients with spinal osteoid osteoma present with radicular pain, gait disturbance, limb atrophy, and painful scoliosis. Painful scoliosis is a well-recognized presentation of spinal osteoid osteoma and osteoblastoma and is considered to be secondary to pain-provoked muscle spasm on the side of the lesion

It is difficult to diagnose spinal osteoid osteoma on the basis of radiographic findings because of the complexity of spinal anatomy and overlapping areas of soft tissue. CT is best for localization of the nidus before treatment is begun. Characteristic MR imaging features of spinal osteoid osteoma are a nidus in the neural arch and bone marrow edema in the involved pedicle and lamina that extends to the posterolateral vertebral body.

References:

Chai JW, Hong SH, Choi JY, Koh YH, Lee JW, Choi JA, et al. Radiologic diagnosis of osteoid osteoma: from simple to challenging findings. Radiographics : a review publication of the Radiological Society of North America, Inc. 2010;30(3):737-49.

Saifuddin A, White J, Sherazi Z, Shaikh MI, Natali C, Ransford AO. Osteoid osteoma and osteoblastoma of the spine. Factors associated with the presence of scoliosis. Spine. 1998;23(1):47-53.