Presentation
Vague headaches.
Patient Data
A cystic lesion measuring 9 x 10 x 12 millimeters occupies the anterior part of the pituitary fossa, displacing the normal pituitary tissue posteriorly and somewhat to the left. It is of low signal intensity on T1, does not enhance, and is of high signal intensity on T2 and demonstrates a 2 to 3 mm hypointense nodule anteroinferiorly.
The optic chiasm may be just contacted in the midline by the dome of the cyst. There is no evidence of extension into the cavernous sinuses.
Scattered throughout the white matter of both cerebral hemispheres, particularly in the frontal lobes, are regions of high T2 signal, which are non-specific but most likely relate to chronic small vessel ischemic change.
T2 hyperintense cyst (yellow dotted line) contains a small inferior T2 hypointense nodule (green arrow). The dome of the cyst just or almost touches the optic chiasm (blue).
Case Discussion
This case demonstrates typical appearances of a Rathke cleft cyst, including the small hypo-intense 'dot' sign, which is said to be pathognomonic.