SHORT REPORT CSF bone cyst in a cervical vertebra JAGWINDER DHALIWAL, NAEEM ABBAS & NAFEES A. HAMID Department of Neurosurgery, Queen Elizabeth Hospital, Birmingham, UK Abstract A 43 year male patient presented with neck pain, upper limb paraesthesia and right foot weakness. A MRI scan revealed a bone cyst involving C4 spinous process, lamina, pedicles and the posterior part of the vertebral body causing focal spinal stenosis. A C4 laminectomy and C3-C5 lateral mass screw fixation was done. Intra-operatively the cyst was found to contain CSF with an associated dural defect. A CSF cervical vertebral cyst has not been previously reported in the literature. The clinical presentation, radiological features and management of this CSF vertebral cyst is discussed. Key words: Cervical spine, CSF leak, spinal cord compression, vertebra, cyst. Introduction Simple bone cysts are common, benign, fluid filled, cystic lesions that occur mostly in the metaphysis of the long bones and are rarely found in vertebrae. 1 They tend to occur more commonly in children and young adults. The cause of vertebral cysts remains unclear. We report the first case of an expanding cervical vertebra (C4) bone cyst containing cerebro-spinal fluid (CSF) in an adult. Intra-operatively the cyst was found to contain clear CSF and the histology revealed normal bone. Case report A 43-year-old male patient presented with neck pain radiating into both arms with a feeling of pins and needles in both hands. He had a mild weakness in the right foot. Neurological examination confirmed hypertonia and hyperreflexia in all four limbs. An MRI scan of the spine revealed a bone cyst expanding the spinous process, lamina, both pedicles and the posterior aspect of the C4 vertebral body (Figs. 1 and 2). Spinal canal stenosis at the level of C4 vertebrae was noted with signal change within the cervical cord at the C3/C4 level. A C4 laminectomy and lateral mass screw fixation from C3 to C5 was done. Intra-operatively as the tip of the spinous process was nibbled, clear fluid started flowing freely from the cavity in the vertebra. As the laminectomy was extended CSF was found between the two tables all along C4. This cavity or ‘CSF tunnel’ was extending into the pedicles and into the body. A defect in the bone or ‘inner table’ was seen with a clear dural defect on the left side, through which there was continuous flow of CSF into the bony cavity. Careful dissection around this bone defect was done to detach the bone from the attached dura at the margins of the dural defect. The dural defect was repaired. Lateral mass screws and rods were inserted bilaterally at C3 and C5. Histology report was of unremarkable bone, connective tissue and skeletal muscle (Fig. 3). On FIG. 1. Saggital T2 weighted MRI images showing the extent of the cyst in the C4 vertebra. Correspondence: Jagwinder Dhaliwal, Department of Neurosurgery, Queen Elizabeth Hospital, Birmingham, UK. E-mail: jagdhaliwal@hotmail.co.uk Received for publication 3 December 2009. Accepted 8 April 2010. British Journal of Neurosurgery, October 2010; 24(5): 600–601 ISSN 0268-8697 print/ISSN 1360-046X online ª 2010 The Neurosurgical Foundation DOI: 10.3109/02688697.2010.487133