A benign cyst located within the pituitary gland of the brain, a Rathke cyst is filled with a thick fluid contained within walls formed by epithelial cells, formed from tissue leftover from the development of the pituitary during the embryonic stage of growth.
During fetal development, two embryonic tissues grow simultaneously: a group of cells known as the Rathke pouch grows upwards while other cells grow inward from the diencephalon. While they eventually grow to the point that they join together, leftover tissue can form an abnormal “cleft” that fills with fluid and create a cyst.
As they rarely produce symptoms or warning signs and are very small, Rathke cysts are only seen when they compress on the pituitary gland, hypothalamus or optic chiasm. When this happen, vision problems occur and an malfunctioning pituitary gland can lead to amenorrhea (an absence of menstruation) in women, an imbalance of water in the body known as diabetes insipidus and other serious conditions.
The most common mode of treatment for a Rathke cyst is surgery using a transsphenoidal approach (through the nostril) in which the cyst is punctured and drained. Long-term monitoring follows to ensure that the cyst has been drained completely and rhinorrhea (a leaking of cerebrospinal fluid through the nostril) is not present.