Background: Extra-axial intracranial brain tumours represent a large cohort of different neoplasms, primarily benign. Despite comprehending a large variety of histological sub-entities with different biological behaviours, extracranial invasion remains a rare occurrence, especially in the parapharyngeal space (PPS). Very few cases of parapharyngeal-invading extra-axial brain tumours are reported in the literature, and little is known about their best operative management, postoperative oncological control and morbidity.
Purpose: To collect and review information on clinical presentation, radiological features, operative techniques and postoperative morbidity of PPS-invading intracranial extra-axial tumours.
Methods: We performed a systematic review and meta-analysis on MEDLINE, Web of Science and Discovery databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines of the current literature reporting group-wise rates of peri-operative complications after resection of extra-axial brain tumours invading PPS as primary outcomes (rate of cranial nerve palsies, vascular injury, CSF leakage, infections, mortality rate and extent of resection).
Results: We systematically reviewed the clinical presentation scenarios, radiological features, operative management and overall rate of complete resection of PPS-invading extra-axial neoplasms, rates of early and late postoperative CN deficits, vascular injuries, venous thrombosis, CSF leak, meningitis and 30 days mortality.
Conclusions: The involvement of PPS by intracranial neoplasms invading extracranial space is a rare condition and a limited amount of data is available to now. Hereby we provided a detailed summary of the presenting symptoms and management options available. Finally, the surgical implications and the morbidity burden of addressing neoplasm in the PPS are discussed.