Thoracic synovial cyst in patient with diffuse idiopathic skeletal hyperostosis

BACKGROUND: Spinal synovial cysts, attributed to degenerative changes of the facet joints, commonly occur at the sites of segmental spinal instability. Here, we present a patient with diffuse idiopathic skeletal hyperostosis (DISH) who developed a T10/T11 synovial cyst contributing to myelopathy that resolved following surgical cyst excision. CASE DESCRIPTION: A 69-year-old male presented with progressive numbness and paraparesis for 2-month duration. The thoracic MR spine showed synovial cyst at the T10/T11 level, while the computed tomography confirmed DISH fusion between the T4 and T10 levels. Following a laminectomy with cyst excision, the patient’s symptoms resolved and he sustained no recurrent dynamic instability. CONCLUSION: A patient with DISH presented with the new onset of myelopathy attributed to a T10/T11 thoracic synovial cyst; following cyst excision, the patient’s myelopahty resolved.