 Again seen is an arachnoid cyst in the right posterior fossa extending into the right cerebellopontine angle cistern that currently measures 5.1 x 2.8 cm, previously 5.2 x 3.2 cm. There is a stable mass effect on the right cerebellar hemisphere and right cerebellar peduncle. There are no areas of abnormal signal in the parenchyma. Evidence of prior small right lateral suboccipital craniotomy for cyst fenestration. No evidence of acute infarct or hemorrhage. No other mass or mass effect. No hydrocephalus. Normal flow-voids are demonstrated in the major intracranial vascular structures.
No significant interval change in arachnoid cyst in the right posterior fossa.