Rathke's Cleft Cysts
Rathke's Cleft Cysts are not tumours, but instead are classified as developmental abnormalities.
In Rathke's Cleft Cyst, the Rathke's pouch eventually forms the pituitary gland and normally closes early in foetal development. A remnant may persist as a cleft that lies within the pituitary gland and occasionally this remnant gives rise to a fluid-filled large cyst called Rathke's Cleft Cyst (RCC).
This condition is more usually seen in adults but can occur at any age. Arachnoid Cysts and Cystic Pituitary Adenomas are other rare cyst-like tumours.
Like craniopharyngiomas, these cysts form during early development of the foetus from a structure known as Rathke's pouch. Small Rathke's cleft cysts are not uncommon and do not usually cause any symptoms. Problems can occur if these cysts enlarge and interfere with pituitary production or exert pressure on the optic chiasm.