Rathke's cleft cyst

A sellar MRI scan was performed on a 1.5T MRI scanner, with SE T1-weighted, FSE T2-weighted and post-gadolinium SE T1-weighted images in the sagittal and coronal planes. A well-circumscribed intrasellar lesion with high signal intensity on spin-echo T1-weighted images, and with mixed hypo- and hyperintense signal intensity characteristics on fast spin-echo T2-weighted images was detected. The lesion did not enhance with contrast. The lesion was surgically removed with a resultant diagnosis of a Rathke's cleft cyst, containing high amounts of cholesterol and protein.

The cysts are usually simple, lined by a single epithelial layer. They may contain variable amounts of protein, mucopolysaccharide, cellular debris, and cholesterol. Their signal intensity may be correspondingly high, low, or intermediate on T1- and T2-weighted sequences depending on the contents of the cystic lesion. Gadolinium enhancement is usually absent, however they may rarely have a thin peripheral enhancement.

Craniopharyngiomas and cystic pituitary adenomas should be considered in the differetntial diagnosis of Rathke's cleft cyst. Craniopharyngiomas have common floccular calcification and usually have contrast enhancing solid or rim-like components. Cystic adenomas usually reveal peripheral contrast enhancement. Rathke's cleft cysts are usually asymptomatic and are discovered incidentally. They may cause pituitary dysfunction, visual disturbances, and headache in rare cases. Most cases of Rathke's cleft cyst are stable and do not need any treatment.