囊性病變之病灶常見於周邊關節，在脊椎內不常見。隨著這些囊腫的增長，特別是與退化相關時，它們可能壓迫附近的神經組織造成病變。本文報告一例腰椎神經節囊腫的病例，並討論臨床、放射學和手術方面的發現。一名 56 歲的女性患者出現持續的下背部疼痛。在三個月內，不適感從臀部延伸至雙腿，主要在左側。腰椎核磁共振影像顯示在的脊椎腔內，有一個囊性病變。在知情同意的情況下，安排手術切除腰椎第五薦椎第一左側椎間黃韌帶以及硬膜外囊性病變，術後病患的疼痛完全消失，神經根功能恢復正常。組織學檢查顯示具有膠原纖維壁的囊腫，缺乏滑膜內皮細胞，符合神經節囊腫的診斷。

Purpose: A 56-year-old female with a medical background presented with persistent lower back pain. Initially attributing the pain to muscle strain, the discomfort extended from her buttocks to both legs, predominantly on the left side, over a span of three months. An MRI of her lumbar spine revealed a round hypointense lesion at L5/S1 on T1WI that brightened on T2WI, suggestive of a left-sided spinal canal synovial cyst. Under the provisional diagnosis of a spinal tumor, she was admitted for surgical intervention. Materials and Methods: With informed consent, a surgical intervention was performed, where the left L5/S1 ligamentum flavum was removed, along with the extradural cystic lesion, relieving pressure on the left S1 root. The histology showed a collagenous fibrous wall, devoid of a synovial lining cell, which is compatible with ganglion cyst. Results: Postoperatively, the patient exhibited a significant improvement in her S1 root pain during a one-month follow-up. This case underscores the importance of accurate diagnosis and timely surgical intervention in managing spinal cystic lesions. Conclusion: Synovial and ganglion cysts are typically found around peripheral joints and tendon covers, yet they are infrequently observed within the spine. While these cysts often originate from the facet joint, there have been instances where they are connected to various spinal structures, including the ligamentum flavum and even the disc. As these cysts grow, particularly when linked with degenerative alterations, they can press against the nearby thecal sac or nerve root. We presented a case of ganglion cyst at the lumbosacral spine and discussed clinical, radiological, and surgical findings with good prognosis.