Case report
A 30-year-old man presented with a one-year history of a progressive, worsening back pain associated to a right intercostal neuralgia, no motor weakness or sphincter disturbance were found. There was no history of fever or trauma. Blood tests were normal and the X-ray rechecks after making the diagnosis showed an unobvious suspect image at the level of the right pedicle of the 12th thoracic vertebra (T12) with disappearance of its normal contours (Figure 1A). Magnetic resonance imaging (MRI) revealed a vascularized mass affecting the right hemivertebral body and posterior arch of T12 with paravertebral soft tissue extension. The spinal cord was mildly compressed (Figure 1B). An extension assessment concluded that it is a primary localization. We performed a computerized tomography (CT) guided biopsy and the diagnosis of EWS was confirmed by histopathology and immunohistochemistry showing uniformly small round cells which were strongly positive to CD99 (Figure 2).
After receiving neo-adjuvant chemotherapy, a new MRI showed vertebral and paravertebral soft tissue mass regression (Figure 1C). According to the WBB surgical staging system, sectors included in the axial T12 imaging were 1 to 6 (part of the body and part of the left posterior arch) and layers of tissue penetration were A to D.
We performed an en bloc vertebrectomy through a double approach surgery: firstly a posterior approach with pedicle screw insertion (2 levels above and 2 levels below), remove of the healthy part of the posterior arch which allow to release the spinal cord from the tumor pseudocapsule , ligation and section of T12 roots (Figure 3A). Secondly a thoraco-phreno-lombotomy to separate the anterior part of the tumor and control the segmental artery. The separation was made by a Gigli saw and the extraction of the vertebra released from all its attachments was possible through a simple rotation of the specimen (Figure 3B and 3C). Reconstruction was performed with interbody free non-vascularized fibular bone grafting stabilized by the posterior instrumentation.
Postoperative course was uneventful. After six weeks of the surgery, the patient started adjuvant chemotherapy and completed treatment with no evidence of disease on re-evaluation at the end of therapy. Three years after surgery, the patient is surviving without neurologic deficit, X-rays revealed consolidation (Figure 4) and with no evidence of recurrence.