Pineal tumors originate from normal cells in the pineal gland which is located in the center of the brain and is involved in the secretion of hormones such as melatonin.
Many tumor types may involve the pineal gland and are thus called pineal tumors. These tumors are classified into two main categories: germ cell tumors or parenchymal tumors. Germ cells are reproductive cells in a human embryo that may travel to different parts of the body during development, such as the brain, chest, and pelvis. If these cells grow abnormally, they can become a tumor, commonly on or near the pineal gland. Parenchymal tumors are made of cells that originate from the pineal gland’s own cells but may be functioning or growing abnormally.
Germ cell pineal tumors include germinomas, choriocarcinomas, and teratomas. Pineal parenchymal tumors include pineocytomas, pineoblastomas, papillary tumors, and pineal parenchymal tumors of intermediate differentiation.
While rare, various other tumors may occur in the pineal region but may not necessarily be categorized as pineal tumors such as other germ-cell tumors meningioma, glioma, ganglioglioma, lipoma, metastases, cysts, and others. Information on these particular tumors can be found on the ABTA website.
Location
The pineal gland is located at the rear of the third ventricle, which is one of the fluid-filled cavities of the brain.
Symptoms
Symptoms are most often caused by blockage of cerebrospinal fluid flow. Common symptoms include headache, lethargy, vision changes, sleep disturbances, nausea and vomiting, tremors, and difficulty with movement. Young people with pineal tumors may experience early or delayed puberty.
Treatment
Standard treatments for pineal tumors include surgery and radiation therapy. The treatment suggested by a doctor depends on the tumor’s type, location, size, grade, and other characteristics. Chemotherapy may also be considered, particularly if the tumor has spread or if it recurs.
In some cases, placement of a shunt (similar to a drain) is used to relieve pressure caused by a buildup of cerebrospinal fluid.
Prognosis
Prognosis means a prediction of outcome. This information is usually based on information gathered from groups of people with the same disease. It is important to remember these statistics are not individualized.
Prognosis of pineal gland tumors is highly variable depending on tumor type and grade, with some types such as germ cell tumors and pineocytomas having a generally good prognosis. About 10% to 20% of these tumors have the potential to spread through the cerebrospinal fluid.
Incidence
Pineal region tumors represent less than 1% of all primary brain tumors; however, they account for approximately 3%of childhood brain tumors. They are more common in males.
Of the germ cell pineal tumors, germinomas are the most common, followed by teratomas. Choriocarcinomas are the least common germ cell pineal tumor. Of the parenchymal pineal tumors, pineoblastomas are the most common, followed by pineocytomas. Papillary tumors and pineal parenchymal tumors of intermediate differentiation are very rare.
Age distribution
With some exceptions, pineal tumors are most commonly diagnosed in children, followed by young adults.
Risk factors
There are no known risk factors for pineal tumors.
Molecular profile
Molecular profiling is the detection of specific genes, proteins, or other molecules in a tumor. This information helps confirm tumor diagnosis, inform treatment options, and predict prognosis. Current research is focused on identifying molecular markers to study and treat pineal tumors.
Additional Resources
Content last reviewed:
October, 2023 by David Gomez, BS and Donald Williams (Will) Parsons, MD, PhD.
