Differential diagnosis of the cystic lesion includes a pituitary or Rathke's cyst or a cystic pituitary adenoma; recently had growth after severe headache; 3-4 month follow up please compare to prior scan for changes, but no endocrine no visual symptoms.. There is interval decrease in size of a T1 hyperintense cystic lesion within the sella that now measures up to 2 mm in height. There is no mass effect upon the optic apparatus or cavernous sinuses and the infundibulum is intact. There is an enlarged retrocerebellar cerebrospinal fluid signal space.
1. Interval decrease in size of the pituitary lesion.2. An enlarged retrocerebellar cerebrospinal fluid signal space may represent an arachnoid cyst.