Pineal gland cyst
The pineal gland is a pine cone shaped gland located in the center of the brain that produces melatonin. Small benign cysts known as pineal gland cysts are commonly found among young adults 20 to 30 years old. Cysts in the pineal gland region of the brain are generally asymptomatic and found more commonly in young women than men.
Definition & Facts
Pineal cysts are benign fluid-filled masses. They are typically small and most often less than 1 centimeter in diameter; however their size may vary and change over time. The cysts most commonly contain proteinaceous fluid and are made up of three layers:
- An inner layer made up of hemosiderin contained in fibrillary glial tissue
- A middle layer that may or may not contain calcification, made up of pineal parenchyma
- An outer layer, made of thin and fibrous connective tissue.
Symptoms & Complaints
Vision impairments such as blurred vision or double vision (diplopia) may occur, and may result in vertigo. In cases of cysts larger than 0.5 cm, difficulties with balance, tingling in the extremities, loss of sex drive, anger problems and panic attacks have been reported.
In more extreme cases, increased pressure due to fluid buildup known as hydrocephalus can cause seizures, memory loss or loss of consciousness, or a change in mental status. When pineal gland cysts are present in children, delayed sexual development may occur.
The precise cause of pineal gland cysts is undetermined; however, there are several theories. Because they are vastly more common among women than men, the first theory is that they are formed due to hormonal changes. This theory is supported by the fact that they tend to appear after puberty, and in cases of cysts that change in size, they have a tendency to grow between puberty and menopause, and shrink after menopause. This is further supported by the fact that in most male patients, the size remains stable and unchanging throughout their lifetime. This is also indicated by evidence that cysts form on this gland when it begins to naturally shrink after puberty.
There are also non-hormone related theories. It is possible that cysts in the pineal gland are a congenital defect, and form during fetal development, indicating that patients with these cysts were predisposed to them from the beginning of the development of their brain.
Lastly, there has been some evidence that cysts may form as a result of a parasitic disease, in which a larva tapeworm may penetrate the pineal gland and form a protective bubble or shell around itself. Inside this shell, the tapeworm allocates all of its metabolic products which forms a cyst that may grow as the tapeworm grows, causing the cyst to be more symptomatic.
Diagnosis & Tests
The vast majority of cases are found by chance on scans performed for unrelated reasons. A physician will start with a complete medical history and family history and a physical examination to determine all symptoms and possible causes for what a patient is experiencing. They may order laboratory tests to determine any metabolic or hormonal imbalances that can be the cause of symptoms.
From here, physicians will request imaging scans such as a CT scan or MRI to confirm a pineal gland cyst diagnosis and check for any masses or tumors. Magnetic resonance imaging (MRI) is the best option for locating a mass and determining the size and shape within the brain. Most physicians will order a magnetic resonance angiography (MRA) in conjunction with the MRI, which uses a contrast dye injected through an IV to look at the blood vessels and blood flow contained in and around the cyst.
A computed tomography (CT) is also used to detect the amount of fluid buildup within the cyst and determine whether or not there is calcification. These are important pieces of information, because the buildup of fluid is what generally causes pressure to be put on adjoining parts of the brain, which is what causes symptoms and will determine whether treatment is necessary.
Treatment & Therapy
In most cases, no treatment is necessary and most individuals with these cysts may never have a symptom or become aware of the cysts existence. In asymptomatic patients with a cyst larger that 10-14 milimeter, a physician may request follow up scans every three to six months to monitor the size and shape of the cyst, and to be sure no related tumor develops.
If the cyst grows or the patient develops symptoms such as hydrocephalus, headaches or vision problems, treatment may become necessary. Treatment options include surgery to remove it and a ventriculoperitoneal shunt may be placed in the brain. Removing the cyst and inserting the shunt can only be done via a craniotomy, meaning to remove part of the skull to gain access to the brain. This is very invasive and done only if absolutely necessary due to growth or symptoms that hinder one's quality of life.
In recent years less evasive options such as aspiration of the fluid of the cyst using ultrasound, or endoscopic procedures have been used. In patients with recurring cysts, radiation treatment may be recommended.
Prevention & Prophylaxis
The best prevention of any long term issues related to these cysts is monitoring and a patient being in tune with their own body and noting any changes with their physician.