Changing signal intensity of a craniopharyngioma

Craniopharyngiomas can present as suprasellar cystic lesion with varied imaging appearance. In magnetic resonance imaging using T1-weighted sequence, the cyst can show hypointense, isointense or hyper intense signals depending on the cyst content. We report a case where the T1 signal intensity of a craniopharyngioma changed over time. The hypointense lesion had become hyper intense in the follow-up scan after six months. Such change in signal intensity is described with Rathke's cleft cyst but has not been reported with craniopharyngioma. The possible reason for this change in signal intensity is discussed.