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.

Pineoblastoma is one type of primitive neuroectodermal tumor (PNET), a group of tumors of the brain that occur in young children. PNETs also include medulloblastomas, neuroblastomas, and ependymoblastomas. One article identified two risk factors for PNETs: exposure to chemicals called N-nitroso before birth (which could occur if the mother drank beer during her pregnancy), and living on a farm for at least one year.

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.

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.

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.

Specialists involved in the care of someone with a pineoblastoma may include:

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

Because each diagnosis is unique, it is difficult to determine the chance of curing a pineoblastoma. Instead, research studies look at how many people are alive and for how long following their diagnosis; these measurements are used to estimate the survival rate. Individuals with a pineoblastoma live an average of 20 months after their diagnosis, and 10% of affected individuals are alive 5 years after their diagnosis. Survival is better when individuals are older than age 3 when diagnosed, when treatment includes complete removal of the tumor during surgery, and when cancercells have not spread to other parts of the body (metastasized).

It has been estimated that about 6 out of 1,000,000 people will develop a pineoblastoma. Females are slightly more likely to be affected than males. Most cases of pineoblastoma occur in children, with only about 10% of cases occurring in adults.