Rathke’s Cleft Cyst

40-year-old male with history of hypopituitarism. There is a well circumscribed, T1-hyperintense, T2/FLAIR-iso- to hypointense, nonenhancing mass within the pars intermedia region of the pituitary gland. The lesion does not restrict diffusion. The signal characteristics are compatible with a a cystic lesion with internal hemorrhage or protein. The differential includes Rathke’s cleft cyst, less likely pituitary adenoma with hemorrhage. On resection, this was found to be a Rathke’s cleft cyst. Rathke’s cleft cysts are non-neoplastic sellar/suprasellar cystic lesions with epithelial linings. They arise from Rathke’s pouch remnants, and are usually of incidental note. They are two times more common in females. While most are asymptomatic, larger lesions can be associated with visual field deficits, pituitary dysfunction, and headaches.