Incidental spontaneous CSF fistula with pterygoid process meningoencephalocele

Abstract

Spontaneous cerebrospinal fluid (CSF) fistula is a rare entity, most commonly occurs at the ethmoid roof, cribriform plate, or the sphenoid sinus; at the perisella, inferolateral or pterygoid recesses. Imaging plays a major role in diagnosis, thereby guiding the treatment of a spontaneous CSF fistula, evolving multiple modalities. We report a case of a patient with spontaneous Meningio-encephalocele presented as an expansile lytic lesion in the left pterygoid body, this patient was successfully treated surgically.

Figure 1

Axial and coronal T2 (A, B), axial FLAIR (C) and axial and coronal T1 SPGR (D, E). A lobulated hypointense T1/ FLAIR and hyperintense T2 left middle cranial fossa lesion was observed in continuity to the left anterior temporal pole, descending to the left sphenoid and the left pterygoid process through a thin CSF column. T1 SPGR showed intralesional signal voids due to turbulent flow.

Figure 2

Axial (A), sagittal (B) and coronal (C) multidetector, thin-section bone algorithm CT images. An expansile lytic lesion was observed in the left sphenoid body, extending to the pterygoid body and the medial and the lateral pterygoid plates. The bony defect seen in the left sphenoid body consisted of cortical permeation and multiple pitting on its inner table.

Figure 3

A post-operative non-enhanced coronal CT images at the level of middle cranial fossa. A soft tissue at the skull base is seen representing multilayer flap with underneath fat patch. Inflammatory changes within the left maxillary sinus is also seen.

Figure 4

A postoperative coronal SSFP (A) and T2 (B). Successful reduction of the left middle cranial fossa meningo- encephalocele is shown. An underlying thin dark layer is demonstrated representing the dural patch.

Figure 5

Timeline table summarizing the chronological sequence of the case report.