Nader Delavari1, Ndi Geh2, Shawn L Hervey-Jumper2, Erin L McKean3, Stephen E Sullivan2. 1. Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan, USA; Department of Neurosurgery, New York University, New York, New York, USA. Electronic address: nader.delavari@nyumc.org. 2. Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan, USA. 3. Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan, USA; Department of Otolaryngology, University of Michigan, Ann Arbor, Michigan, USA.
Abstract
BACKGROUND: Synovial cysts are cystic masses lined with pseudostratified columnar cells and containing clear or xanthochromic fluid. Although they are commonly encountered in the lumbar spine, synovial cysts infrequently occur in the cervical spine and rarely involve the odontoid process. The causes of synovial cysts of the odontoid process are unknown, but growth of synovial rests, proliferation of multipotent mesenchymal cells, atlantoaxial instability, and trauma are thought to play a role. CASE DESCRIPTION: We present 3 cases of atlantoaxial cysts with the associated radiographic features, surgical management, and clinical outcomes. No patient had rheumatoid arthritis. In all cases, preoperative differential diagnosis included neoplastic pathologic changes. Two patients underwent odontoidectomy through either an endonasal or a transoral approach, followed by posterior occipitocervical fusion. The third patient underwent an endoscopic transsphenoidal approach for cyst decompression. CONCLUSIONS: Tissue diagnosis is important in confirming pathologic analysis because synovial cysts have radiographic characteristics similar to those of a wide variety of neoplasms of the craniovertebral junction.
BACKGROUND: Synovial cysts are cystic masses lined with pseudostratified columnar cells and containing clear or xanthochromic fluid. Although they are commonly encountered in the lumbar spine, synovial cysts infrequently occur in the cervical spine and rarely involve the odontoid process. The causes of synovial cysts of the odontoid process are unknown, but growth of synovial rests, proliferation of multipotent mesenchymal cells, atlantoaxial instability, and trauma are thought to play a role. CASE DESCRIPTION: We present 3 cases of atlantoaxial cysts with the associated radiographic features, surgical management, and clinical outcomes. No patient had rheumatoid arthritis. In all cases, preoperative differential diagnosis included neoplastic pathologic changes. Two patients underwent odontoidectomy through either an endonasal or a transoral approach, followed by posterior occipitocervical fusion. The third patient underwent an endoscopic transsphenoidal approach for cyst decompression. CONCLUSIONS: Tissue diagnosis is important in confirming pathologic analysis because synovial cysts have radiographic characteristics similar to those of a wide variety of neoplasms of the craniovertebral junction.