Intracranial glioependymal (neuroglial) cysts: a systematic review.

BACKGROUND: Glioependymal cysts (GECs) are benign intracranial cysts that have been rarely reported in the literature. The exact pathogenesis of these developmental anomalies is controversial. Moreover, the terminology used to name GECs and other intracranial cysts is confusing because they are undistinguishably reported under a variety of names. The available information in the literature about GECs is scarce, and for this reason, a detailed description about these uncommon lesions is necessary. METHODS: An illustrative case is presented; in addition, a PubMed and Scopus search adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed to include studies reporting patients with GECs. Different information was analyzed in these patients to describe the characteristics of this condition. In addition, different sources of literature were analyzed to complete the description of this clinical entity. RESULTS: The literature review yielded 26 cases of patients with intracranial GECs showing a diversity of clinical manifestations. All studies were case reports or small case series. Different characteristics of GECs are described. Moreover, the authors suggest an updated classification of intracranial benign cysts. CONCLUSIONS: The data collected from this review shows that GECs are rare and very often are erroneously named. They are congenital benign lesions with a neuroectodermal origin that share many radiological characteristics with a variety of intracranial benign cysts. The definite diagnosis of GECs is confirmed by the presence of a glial layer in the cyst wall at histological examination. The appropriate surgical technique should be selected according to the location of the cyst and its proximity to the ventricles or subarachnoid space.