Presentation
Mid thoracic back pain for the last 6 months with no evidence of trauma, weight loss or fever. Partial relief with analgesics was reported.
Patient Data
Note: This case has been tagged as "legacy" as it no longer meets image preparation and/or other case publication guidelines.
Sagittal reformatted CT shows a focal lytic lesion (nidus) with central density, suspicious of calcification in the right T8 pedicle, with very minimal sclerotic reaction seen surrounding the nidus.
Sagittal T2W image of the thoracic spine shows a focal area of hyperintensity in the posterior aspect of the right side of T8 vertebral body with involvement of the right pedicle.
Coronal STIR images show abnormal hyperintense signal in the right side of T8 vertebral body and its right pedicle.
Axial T2W image of the thoracic spine shows a focal area of hyperintensity in the posterior aspect of the right side of T8 vertebral body with involvement of the right pedicle.
Sagittal T1W image of the thoracic spine shows a focal area of hypointensity in the posterior aspect of the right side of T8 vertebral body with involvement of the right pedicle. Additionally noted is an extension of the abnormal signal into the right paraspinal soft tissues.
Sagittal post-contrast image of the thoracic spine shows an abnormal homogeneous enhancement in the posterior aspect of the right side of T8 vertebral body with involvement of the right pedicle.
Axial post-contrast image of the thoracic spine shows abnormal enhancement in the posterior aspect of the right side of T8 vertebral body and of the right pedicle. Additionally noted is enhancement of the right paraspinal soft tissues.
Case Discussion
Spinal osteoid osteomas usually affect the posterior elements. In the spine, the lumbar spine followed by the cervical and then the thoracic spine are most commonly affected. The patients are usually young and present with back pain. A high index of suspicion is needed for this entity especially with MRI as the nidus and surrounding reactive sclerosis may not be diagnosed unless the lesion is suspected and then a CT is done.
On MRI, an area of edema in the posterior and lateral aspect of a vertebral body with pedicle involvement is classically seen. This region of signal abnormality shows T1 and T2 prolongation with no fatty elements within and shows homogeneous contrast enhancement. The degree of surrounding edema and enhancement is of varying grades and involvement of the paraspinal soft tissues with enhancement is classified as grade IV.
A CT is also needed after the MRI to clearly identify the nidus and the surrounding lucency. The sclerotic reaction can also be well assessed.