Cerebellopontine angle pilocytic astrocytoma in adults: A systematic review

Background: In adults, the cerebellopontine angle (CPA) pilocytic astrocytoma (PA) is very rare. This tumor has radiological features similar to those of a vestibular schwannoma in the few cases reported in the literature. Methods: In this study, we conducted a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol and scrutinized all original studies pertaining to pontocerebellar angle PA in adult patients. We conducted an analysis of the clinical, radiological, and molecular components of all eligible articles. We have also reported a case involving a 67-year-old male individual in whom the PA exhibited radiological characteristics similar to an epidermoid cyst. Results: After the screening phase, we found four cases of PA of the pontocerebellar angle. Three cases were identified that resembled vestibular schwannoma; however, in our case, the tumor resembled an epidermoid cyst. These uncommon tumors exhibit distinctive histological patterns and molecular characteristics (adenosine triphosphate dependent helicase (ATP- dependent helicase)+, Isocitrate dehydrogenase 1−), rendering them a potential differential diagnosis for glioblastoma (GBM). Conclusion: The CPA PA has rarely been found in adult patients and should be considered in the differential diagnosis of vestibular schwannoma and epidermoid cysts. In these rare cases, the histological characteristics of PA are significant for the differential diagnosis of GBM.