Rathke Cleft Cysts are benign, fluid-filled sacs often found incidentally during brain imaging. Understanding their nature, potential for growth, and management is important for those diagnosed.
Understanding Rathke Cleft Cysts
A Rathke Cleft Cyst (RCC) is a non-cancerous, fluid-filled growth located in the pituitary gland region at the base of the brain. These cysts are congenital, meaning present from birth. They originate from Rathke’s pouch, a structure that forms during embryonic development; if this pouch does not fully close, a space can remain where a cyst may form.
Most Rathke Cleft Cysts are relatively small, often measuring between 2 to 40 millimeters. Many individuals remain without symptoms unless discovered incidentally during a brain scan. These cysts are distinct from other pituitary tumors because they are benign and grow through fluid accumulation, not uncontrolled cell division.
The Nature of Growth
While many Rathke Cleft Cysts remain stable, some can grow. This growth is typically slow and gradual, often due to fluid accumulation secreted by the cells lining the cyst. Rapid growth is uncommon; studies indicate approximately 5.3% of incidentally discovered RCCs may increase in size.
Factors contributing to cyst growth include increased fluid production, or less commonly, an inflammatory reaction or hemorrhage within the cyst. The exact mechanisms are not fully understood, though some research suggests smoking status and age can influence rapid growth. Many cysts monitored with MRI scans remain stable or can even spontaneously shrink. However, if a cyst enlarges, it can begin to press on surrounding brain structures.
Symptoms and Detection of Growth
If a Rathke Cleft Cyst grows, symptoms arise from the cyst pressing on nearby structures. Common symptoms include headaches and visual disturbances. Visual changes can manifest as blurry vision, vision loss, or loss of peripheral vision, occurring when the cyst compresses the optic nerves or optic chiasm.
Growth can also put pressure on the pituitary gland, leading to hormonal imbalances. This may result in symptoms such as fatigue, changes in body weight, low sex drive, irregular menstrual periods, or excessive thirst and urination. Cyst growth is primarily detected through follow-up Magnetic Resonance Imaging (MRI) scans, often performed at regular intervals to monitor the cyst’s size and characteristics.
Management Considerations
For incidentally identified, asymptomatic Rathke Cleft Cysts, watchful waiting with periodic MRI scans is the most common management approach. If a cyst grows and causes symptoms, intervention is considered. Primary treatment involves surgical drainage or removal of the cyst.
This surgery is often performed using a minimally invasive transsphenoidal approach, typically through the nose. The goal is to relieve pressure on surrounding structures and alleviate symptoms. While headaches and visual problems often improve after surgery, new hormonal deficiencies can sometimes develop post-operatively, which may require hormone replacement therapy. Careful consideration of risks and benefits is made, as many cysts do not require active treatment, and surgical recurrence is possible in a small percentage of cases.