Pineoblastoma is a type of cancerous (malignant) tumor that grows in a part of the brain known as the pineal gland. It occurs mainly in children. Symptoms of pineoblastoma include a buildup of fluid around the brain (hydrocephalus), headaches, nausea, and difficulty with eye movement. Without treatment, pineoblastomas can cause weakness and difficulty controlling movement. The long term outcome depends on the age at diagnosis, the size of the tumor, and if the tumor has spread outside the brain (metastasized). The cause of pineoblastoma is unknown, but specific inherited genetic variants in two genes, RB1 and DICER1 can increase the risk for a pineoblastoma. Diagnosis is based on the symptoms, clinical exam, and imaging studies. In addition, a biopsy is often done to examine a small piece of tumor tissue under the microscope. Treatment of pineoblastoma includes surgery to remove as much of the tumor as possible, as well as radiation therapy and chemotherapy.

The exact cause of pineoblastomas is unknown. Most occur by chance (sporadic cancer). Rare cases of pineoblastoma are related to inherited genetic variants in either the RB1 or DICER1 gene. Variant in these genes increase the risk for pineoblastoma and other cancers. However, not everyone who has an RB1 or DICER1 gene variant will develop cancer.

The following list includes the most common signs and symptoms in people with pineoblastoma. These symptoms may be different from person to person. Some types of cancer have few or no symptoms, and some may only have symptoms in more advanced stages. This list does not include every symptom or feature that has been described in this cancer. Symptoms of pineoblastoma may include:

• Headaches
• Nausea and vomiting
• Trouble with eye movements
• Excess fluid buildup around the brain (hydrocephalus)

Pineoblastoma usually occurs in children, but may occur in adults as well. As the tumor grows, it can cause weakness and trouble controlling movements. The long term outcome depends on how early the cancer is diagnosed, the size of the tumor, and whether the tumor has spread outside the brain.

Treatment for pineoblastoma typically involves surgery, radiation therapy, and chemotherapy. Depending on the size of the tumor, chemotherapy or radiation may be done first to help shrink the tumor. Specialists involved in the care of someone with a pineoblastoma may include:

• Radiologist
• Neurosurgeon
• Neurologist
• Medical oncologist
• Radiation oncologist

A pineoblastoma is diagnosed based on the symptoms, a clinical exam, and imaging studies such as an MRI or CT scan of the head. In addition, a small piece of the tumor may be removed for study under a microscope (biopsy).

A small number of pineoblastomas may be caused by an inherited predisposition, meaning that changes (variants) in a gene inherited from a parent may increase the chance that a pineoblastoma could develop. Inherited genetic variants in either the RB1 gene or the DICER1 gene can increase the risk for developing a pineoblastoma. However, not everyone who has an RB1 or DICER1 gene variant will develop cancer.  Gene variants in the RB1 or DICER1 gene are inherited in an autosomal dominant pattern. All individuals inherit two copies of each gene. Autosomal means the gene is found on one of the numbered chromosomes found in both sexes. Dominant means that only one altered copy of a gene is necessary to have the condition. The variant can be inherited from either parent. Sometimes an autosomal dominant condition occurs because of a new genetic variant (de novo) and there is no history of this condition in the family.    Each child of an individual with an autosomal dominant gene variant has a 50% or 1 in 2 chance of inheriting the variant and the inherited cancer predisposition. People who inherit a dominant cancer predisposition will be at increased risk for cancer, but there is also a chance that they may never develop cancer. The factors that influence who will get cancer and who won't are still not well understood.