Overview and Facts about Pineal Tumor
A pineal tumor is a rare tumor that forms in or around the pineal gland—the small pinecone-shaped gland located in the midbrain area. The pineal gland produces melatonin, which is the hormone that helps regulate circadian rhythms (the physical, mental and behavioral changes that take place during the 24-hour cycle; sleeping at night and waking up in the morning is an example of a light-related circadian rhythm).
Pineal tumors account for less than one percent of all primary brain tumor diagnoses and are commonly seen in children and young adults between 20 and 40 years old.
There are three main types of pineal tumors:
- Pineocytoma: a slow-growing tumor that is typically benign (noncancerous)
- Pineoblastoma: a more aggressive malignant (cancerous) tumor
- Mixed pineal tumor: a combination of slow-growing and fast-growing tumors
Signs and Symptoms of Pineal Tumor
As these tumors grow, they can compress or invade surrounding brain structures. Due to their location in one of the fluid-filled cavities of the brain, known as the third ventricle, they may block the cerebrospinal fluid flow, causing excessive buildup of fluid on the brain (hydrocephalus).
Causes and Risk Factors of Pineal Tumor
The exact cause of pineal tumors is unknown. However, researchers believe that mutations in the RB1 gene inherited from one parent may increase the risk. Exposure to radiation and environmental exposure to certain chemicals may also play a role.
Tests and Diagnosis of Pineal Tumor
A neurologist may use imaging studies, primarily magnetic resonance imaging (MRI) scans and computed tomography (CT) scans to make the diagnosis. These scans can show the presence and size of the tumor, and any indication of hydrocephalus. A biopsy of the tumor cells may also be recommended to determine the type of tumor, as well as to help decide the best treatment plan.
Treatment and Care for Pineal Tumor
Treatment for pineal tumors varies depending on the type and size of the tumor. When neurological surgery is recommended, neurosurgeons use advanced, minimally invasive surgical techniques whenever possible. The goal is to remove all of the tumor or as much as possible for the best outcome.
When there is cerebrospinal fluid buildup, the placement of a shunt (a narrow piece of tubing) can help drain the fluid and relieve pressure.
In some cases, stereotactic radiosurgery may be recommended for the treatment of small tumors. This nonsurgical alternative uses advanced imaging technologies and computer guidance to deliver high-power, precisely targeted radiation to the tumor.