Sacral bone cyst treatment resulting in paraplegia.

Accepted 4 January 2018 DesCripTion A 50-year-old man with a stage 1 solitary right sacral plasmacytoma complained of a sharp, burning lower back pain with radiation into his right lower extremity which worsened with movement. He had initially undergone localised radiation therapy, but the pain did not resolve. Postradiation CT-guided biopsy showed persistence of malignant plasma cells, and he then underwent seven cycles of VRD (dexamethasone, lenalidomide and bortezomib) chemotherapy. After chemotherapy, an 18-fluorodeoxyglucose-positron emission tomography/ CT scan showed a new area of uptake in the right sacral ala near the initial plasmacytoma. A subsequent CT-guided biopsy was non-diagnostic, and repeat imaging at the time of presentation showed no interval growth. The lesion was believed to be a residual cyst with inflammatory changes from radiotherapy. Examination revealed no neurological deficits. The patient’s pain was thought to be secondary to the cyst (figure 1) and was not relieved with physical therapy, duloxetine or opioid pain medication. He was referred to orthopaedics, who recommended cyst aspiration and bone grafting. In the operating room under fluoroscopy, a trephine was placed into the right sacral bone cyst. Bloody fluid was aspirated from the cyst, and the resulting cavity was injected with calcium sulfate-calcium phosphate composite bone graft (PRO-DENSE, Wright Medical Technology, Arlington, Tennessee, USA). Two hours after his procedure, the patient began to experience severe back pain, lower extremity weakness, and a loss of bladder and bowel function. A CT scan demonstrated intraspinal and intradural extension of a bone substitute material occupying the entirety of the spinal canal through L1 with resultant effacement of the nerve roots of the cauda equina and compression of the terminal cord (figure 2). On physical exam, his temperature was 36.2°C, heart