Ligamentous cyst is a cystic formation arising from degeneration of ligamentous structures all around the spinal cord. They can cause spinal cord compression, like synovial cyst. Unlike synovial cyst, there is no spinal instability in pathogenesis of ligamentous cyst. Differential diagnosis through pre-operative MRI is difficult and intraoperative findings plus histopathology are crucial to achieve a diagnosis. In this case report, we deal with a rare case of cervical junction ligamentous cyst. A 59-year-old Caucasian female was admitted in our ward with left-sided hemiparesis, cervical pain, and upper limb diffused paresthesias, due to an oval-shaped formation into ALL, of 13 mm in maximum diameter, with peripheral contrast enhancement. The patient underwent, under general anesthesia, a surgery through a posterolateral suboccipital approach which aimed to decompress the spinal cord and to drain the cyst with total removal of the compression by emptying the cyst and fulfilling it with muscle graft and glue. No posterior fixation was needed. After the surgery, symptoms improved and a post-operative MRI scan demonstrated the good result of the surgery.
Keywords: Atlanto-axial malformation; Cervical spine; Ligamentous cyst; Spinal compression.