Arachnoid cyst fenestration followup. There are postoperative findings from prior suboccipital craniectomy for fenestration of an arachnoid cyst just superior to the cerebellar vermis. The lesion has increased in size, measuring up to 16 mm, previously 12 mm. There is associated mild mass effect on the tectum and superior cerebellum, without underlying signal abnormality. There is no restricted diffusion to suggest acute ischemia. There is no evidence of acute intracranial hemorrhage. The ventricles are within normal limits in size and configuration. There is no abnormal intracranial enhancement. The major flow-voids are preserved. There are mucosal retention cysts in the left maxillary sinus. The orbits, paranasal sinuses, calvarium, and overlying scalp are otherwise unremarkable.
Interval increase in size of posterior fossa arachnoid cyst without evidence of complication.I personally reviewed the Images and/or procedure with the Resident/Fellow and agree with this report.