Indian Journal of Radiology and Imaging Indian Journal of Radiology and Imaging

MUSCULOSKELETAL
Year
: 2003  |  Volume : 13  |  Issue : 3  |  Page : 291--293

Osteoid osteoma of the cervical spine : Case report and review of literature


KS Murugan 
 Clarity MRI Centre, 163, Gokale Street, Ramnagar, Coimbatore-641 009, Tamilnadu, India

Correspondence Address:
K S Murugan
Clarity MRI Centre, 163, Gokale Street, Ramnagar, Coimbatore-641 009
India




How to cite this article:
Murugan K S. Osteoid osteoma of the cervical spine : Case report and review of literature.Indian J Radiol Imaging 2003;13:291-293


How to cite this URL:
Murugan K S. Osteoid osteoma of the cervical spine : Case report and review of literature. Indian J Radiol Imaging [serial online] 2003 [cited 2021 Jan 18 ];13:291-293
Available from: https://www.ijri.org/text.asp?2003/13/3/291/28700


Full Text

 INTRODUCTION



Osteoid osteoma, a benign osteoid forming tumour may be found in any bone in the body. 10% of cases involve the spine. Lumbar spine is the commonest site (59%) with the neural arch being the usual location (75%). We report two cases of cervical spine osteoid osteomas diagnosed with MRI, one involving the vertebral body and the other involving the neural arch. The atypical MR imaging features and the importance of CT scan in the diagnosis are highlighted.

Case I:

A 12 years old boy presented with severe pain in the cervical region and torticollis.

Neurological examination was unremarkable with normal muscle strength. The laboratory findings were within normal limits. Radiographic evaluation of cervical spine was essentially normal. MRI with T1 weighting [Figure 1] demonstrated diffuse low signal intensity within the pedicle and lamina of C4 vertebra on the right side in the parasagittal sections, with corresponding high signal on T2 weighting [Figure 2]. No abnormal soft tissue component was seen. CT demonstrated sclerosis of the right pedicle and lamina surrounding a lytic lesion with central calcific nidus [Figure 3]. The radiological diagnosis was osteoid osteoma.

Patient underwent hemilaminectomy. Histology demonstrated a circumscribed focus of vascularised fibro-connective tissue containing ossification, consistent with osteoid osteoma.

Case 2:

A 21 years old male presented with neck pain for the past 5 months. The presentation and results of initial evaluation were similar to the first case. MRI with T1 weighting [Figure 4] showed diffuse low signal intensity within the left half of C4 vertebral body with hyperintensity on T2 weighting [Figure 5]. CT showed sclerosis in the left half of vertebral body with a central lucent nidus [Figure 6], consistent with osteoid osteoma. No central calcification was noted in this case. Partial corpectomy and histological evaluation confirmed the diagnosis.

 Discussion



Described by Jaffe in 1935, osteoid osteoma is a benign skeletal neoplasm consisting of a highly vascularised nidus of connective tissue surrounded by sclerotic bone. The nidus is usually less than 15mm and when larger is classified as osteoblastoma.

Osteoid osteoma comprises 10% of all benign bone tumors and only 1% of all spinal tumors [1]. Jackson reviewed 860 cases of osteoid osteoma and found that 10% occurred in the spine: 59% occurred in the lumbar spine, 27% in the cervical spine, 12% in the thoracic spine and 2% in the sacrum. The posterior element was involved in 75% of cases and only 7% occurred in the vertebral body.

There have been only six previously reported cases of osteoid osteoma of cervical vertebral body [2],[3]. In one of our two cases the lesion was involving the vertebral body and the other involving the lamina.

Patients with osteoid osteoma are usually younger and rarely present after 30years of age. Approximately half of all cases present between the ages of 10 and 20 years. The male: female ratio is 2-4:1.

Local pain and tenderness is the presenting symptom in over 95% of cases. Scoliosis and torticollis may be presenting features in thoraco-lumbar and cervical spine regions.

The complex spinal anatomy may make osteoid osteoma almost impossible to visualize on conventional radiography [4]. Radionuclide bone scanning is more reliable than conventional radiography. The intense osteoblastic activity within the nidus results in a focal uptake surrounded by a decreased uptake owing to the sclerotic bone creating the 'Double density' sign that is typical [5].

CT is the most reliable imaging modality in the diagnosis [6]. Typically dense sclerosis surrounding a lytic lesion that may have a central calcific nidus is noted.

On MRI, osteoid osteoma demonstrates a heterogeneous appreance. The calcification within the nidus and surrounding bony sclerosis are of low signal intensity on short TR and long TR images [7]. Hence, the nidus is usually less conspicuous on MR images than CT scans depending on the extent of calcification. In contrast, marrow edema and soft tissue inflammation are usually well depicted by MR imaging as high signal intensity on long TR images [8].

In conclusion osteoid osteoma of cervical spine is a rare entity. CT scan is the imaging modality of choice for the diagnosis. However in the given clinical context of patients presenting with neck pain, MRI is more commonly performed to rule out disc disease. Therefore it is imperative to recognize the important but atypical MR imaging features of this entity. CT scan will be then the most valuable complimentary investigation to confirm the diagnosis.

References

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