Thoracoscopic en bloc extirpation for subperiosteal osteoid osteoma of thoracic vertebral body: a rare variety and its therapeutic consideration.

BACKGROUND CONTEXT: Osteoid osteoma is a rare benign osteoblastic tumor. Approximately 10% to 20% of osteoid osteomas occur in the spine with a high trend to involve the posterior components; in turn, vertebral body involvement is uncommon. Osteoid osteoma has been classified into cortical, cancellous, and subperiosteal subtypes according to the localization of the nidus. Subperiosteal osteoid osteoma is extremely rare and has been reported mainly in the femoral neck and small bones of the hands and feet. To the best of our knowledge, subperiosteal osteoid osteoma arising in spine has never been reported previously.

PURPOSE: To illustrate a rare case of a 23-year-old female with painful scoliosis because of subperiosteal osteoid osteoma of ninth thoracic vertebra that was treated by thoracoscopic intervention.

STUDY DESIGN/

SETTING

A case report and review of literature.

METHODS

Magnetic resonance imaging revealed the inflammation/edema pattern intensity at right side of both 9th and 10th thoracic vertebrae. Computed tomography demonstrated the round radiolucency surrounded by reactive bone formation (nidus) at the right anterolateral aspect of ninth thoracic vertebra. Taken all findings including anatomical localization of the lesion into consideration, we decided to use thoracoscopic intervention. Improvement of scoliosis was achieved 2 months after surgery. At the time of final follow-up, the patient was free of symptom and there was no clinical and radiologic evidence of recurrence of the tumor 1.5 years postoperatively.

RESULTS

Thoracoscopic intervention achieved en bloc extirpation of the nidus after partial removal of the 10th rib head. Thoracoscopic treatment has never been reported as a treatment modality of spinal osteoid osteoma. Within a few hours after the operation, the pain disappeared completely. Histopathological examination revealed that extracted lesion was compatible with osteoid osteoma.

CONCLUSIONS

The lesion described here demonstrates an extremely rare variety of spinal osteoid osteoma, which was successfully treated by an unprecedented thoracoscopic intervention. This alternative surgical approach enabled en bloc extirpation and effective correction of scoliosis while achieving a cosmetic satisfaction.