Mega Cisterna Magna: Current Perspectives and Future Directions—A Literature Review

The posterior fossa anomaly known as mega cisterna magna (MCM) is defined as an enlarged cisterna magna that is more than 10 mm in the anteroposterior dimension, without concomitant vermian or cerebellar malformations. Although this condition is usually discovered incidentally during prenatal or neuroimaging examinations, its clinical significance and long‐term effects are still being studied and discussed. The prognosis and treatment of MCM depend on its differentiation from other posterior fossa malformations, including Blake’s pouch cyst, Dandy–Walker variant, and arachnoid cysts. In addition to exploring debates surrounding MCM and potential clinical applications, this review attempts to summarize the state of knowledge currently available on the anatomical, embryological, clinical, and radiological aspects.