Gas-Filled Intradural Cyst within the Cauda Equine

Abstract

A case of radicular pain that resulted from a gas-filled intradural cyst in an 80-year-old male is described. Temporary improvement of radicular pain was observed after CT-guided aspiration. However, recurrent radicular pain led to surgical treatment. In this report, the authors document the radiologic and intraoperative features of a gas-filled intradural cyst that migrated into the nerve root, and propose an optimal treatment plan based on a review of the literature.

Keywords: Cyst; Gas; Intradural; Treatment plan.

Fig. 1

A : Computed tomography scan reveals not only the vacuum phenomena at the L2-3 and L3-4 levels but also intradural gas collection at the L2-3 level. B : Enhanced magnetic resonance image shows a peripheral enhancement of the cyst (arrow).

Fig. 2

A : Computed tomography-guided needle aspiration of the intradural gas-filled cyst. The need-le tip is located in the gas-filled cyst. B : There is the remarkable reduction of the cyst and only a sc-anty amount of air in the cyst after the aspiration. C : A month later, axial computed tomography scan shows reaccumulation of the gas-filled intradural cyst.

Fig. 3

Intraoperative discography demonstrates the contrast medium flow into the intradural cyst, and partially fills the cyst. Additionally, it shows the air-fluid level in the cyst.

Fig. 4

Intraoperative photographs after opening of the dural sac. A : The terminal portion of the intradural nerve root is severely bulging out. B : After removal of the cyst, there is a communication with the L2-3 disc space via a fistula at the ventral dura mater. C : The fistula is sutured with non-absorbable thin nylon thread.

Fig. 5

Histological examination reveals multifocal infiltration of chronic inflammatory cells and fibrosis within degenerative fibrocartilage (H & E, ×100).