A Case of a Spinal Extradural Arachnoid Cyst
Yousuke Kojimahara1, Shintaro Tsuge1, Keiji Hasegawa1
1Department of Orthopaedic Surgery, Toho University School of Medicine, Tokyo, Japan.
Insights
A rare spinal extradural arachnoid cyst (SEAC) caused chronic hip pain. Surgical treatment involving cyst removal and ligation of its communication pathway provided significant pain relief and prevented recurrence.
Area of Science:
- Neurosurgery
- Spinal Surgery
- Radiology
Background:
- Spinal extradural arachnoid cysts (SEACs) are rare pathologies causing neurological symptoms.
- Chronic hip and buttock pain can be indicative of spinal abnormalities.
Observation:
- A 49-year-old woman presented with 3-year history of worsening hip and buttock pain.
- MRI revealed a cystic lesion at the T12 vertebral level with T1-low, T2-high signal intensity.
- CT imaging demonstrated severe vertebral scalloping and a dorsal dural canal lesion.
Findings:
- Surgical exploration identified a 60x25mm cystic lesion with a communication pathway near the T12 nerve root.
- Histopathological diagnosis confirmed an arachnoid cyst.
- Ligation of the communication pathway and cyst excision resulted in symptom resolution.
Implications:
- This case highlights the importance of surgical intervention for symptomatic SEACs.
- Contrast-enhanced CT is valuable for pre-operative localization of the cyst's communication tract.
- Effective surgical management can lead to long-term pain relief and prevent cyst recurrence.
Abstract:
The patient was a 49-year-old woman with a chief complaint of hip and buttock pain that had persisted for 3 years. She visited our hospital for aggravation of the pain. Percussion tenderness of the spinous process was observed and a T1-low, T2-high cystic lesion was detected on the dorsal side of the dural canal at the 12th thoracic vertebral level on MRI performed by a previous physician. Plane CT showed severe scalloping at the same level. During laminectomy for the 11th and 12th thoracic vertebrae, a cystic lesion of about 60 × 25 mm was noted on the dorsal side of the dural canal, with a communication pathway with the cyst present near the left 12th nerve root bifurcation. This pathway was ligated and the cyst was excised. The histopathological diagnosis was an arachnoid cyst. Pain improved after surgery, and as of 10 months after surgery, the cystic lesion has not recurred. A spinal extradural arachnoid cyst (SEAC) is a relatively rare disease. This case shows that surgical ligation of a communicating tract and cystectomy are necessary and contrast-enhanced CT was useful for the identification of the position of the communication pathway before surgery.
