Pineal Region Tumors

Pineal region tumors are rare tumors that primarily occur in children and younger adults (between 20-40 years old).

These tumors originate in the pineal gland, an endocrine gland located near the center of the brain. The pineal gland is responsible for secreting hormones like melatonin which regulates sleep patterns, among other functions.

Symptoms of pineal region tumors can vary, depending on the size and location of the tumor. Some of the more common symptoms include the following:

Headaches
Nausea or vomiting
Vision problems

Headaches, nausea, and vomiting can be signs of increased intracranial pressure, which can occur if a tumor is large enough to block the flow of cerebrospinal fluid (CSF) in the brain. Coordination of eye movement can be affected due to pressure upon the midbrain, which is adjacent to the pineal gland.

How common are pineal region tumors?

Pineal region tumors can occur in both younger adults and children, accounting for 2.6% of all primary brain tumors in children (ages 0-14 years) and 1.2% of primary brain tumors in adolescents and young adults (ages 15-39 years).¹ Overall, these are rare tumors. In 2019, an estimated 190 new cases were diagnosed in the United States.¹

What are the different types of pineal region tumors?

Tumors of the pineal region can be classified according to a variety of factors, including by grade and histological characteristics. The tumor subtypes are listed below:

Tumors from the Pineal Gland:

Pineocytoma (WHO grade I) is a slow-growing tumor of the pineal region that arises from pinealocytes, the cells that secrete melatonin in the pineal gland.
Pineal parenchymal tumor of intermediate differentiation (PPTID, WHO grades II-III) is a rare subtype of pineal region tumor, with a prognosis that falls between pineocytomas and pineoblastomas.
Papillary tumor of the pineal region (WHO grades II-III) is a rare subtype of pineal region tumor that arises from ependymal cells in the pineal gland.
Pineoblastoma (WHO grade IV) is the most rapidly growing and aggressive subtype of pineal region tumor. This subtype can also spread more easily through the brain and CSF around the brain.

Germ Cell Tumors:

Germ cells originate from undifferentiated cells early in development, and can form tumors in the pineal region. These tumors can be of several different types, but are usually separated into germinoma and non-germinomatous germ cell tumors (NGGCT)
Germinomas are more common in boys and are usually treated with a combination of chemotherapy and/or radiation.
NGGCTs include several types: embryonal carcinoma, yolk cell tumor, choriocarcinoma, and teratoma. Most of these tumors demonstrate aggressive growth and require a variety of treatments.

What are the treatment options for pineal region tumors?

When a tumor is discovered in the pineal region. The first step is to obtain blood, and in some situations, cerebrospinal fluid (CSF) samples. Germ cell tumors will produce proteins that can be detected in the blood or CSF. If there is a strong likelihood of a diagnosis of a NGGCT, the initial step is chemotherapy. If a germinoma is suspected, a surgical biopsy is usually required to confirm the diagnosis prior to treatment.

For other pineal tumors, and for those where the diagnosis is unclear, surgery is the first. Depending on the appearance of the tumor, sometimes a stereotactic (or needle) biopsy may be done to obtain a small piece of tissue to confirm the actual diagnosis. In other situations, a larger procedure (craniotomy) is performed to obtain tissue and also remove as much of the tumor as possible, while protecting critical brain function.

For patients experiencing hydrocephalus, surgical removal of the tumor may be enough to relieve the increased brain pressure. In some cases, a temporary or permanent drainage system (called a ventriculoperitoneal shunt) may be placed to remove excess fluids from the brain. Sometimes, a diversionary procedure, known as an endoscopic third ventriculostomy (ETV), allows CSF to leave the brain ventricles through an alternate route thereby relieving the hydrocephalus.

Additional treatment like radiation or chemotherapy will depend on a variety of factors, including tumor subtype and grade. For example, some pineocytomas may not require additional therapy if complete resection is possible. In contrast, pineoblastomas are more commonly treated with a combination of surgery, radiation therapy, chemotherapy, and in some cases myeloablative chemotherapy with stem cell rescue.

What are the outcomes for patients with pineal region tumors?

The outcomes for patients with pineal tumors can vary, depending on a variety of factors. Characteristics of the tumor itself can greatly affect outcomes. Such features may include tumor subtype and histological characteristics. In general, for both adults and children, the best patient outcomes occur when the tumor can be completely removed. Complete removeal of pineocytomas is usually curative.

Germ cell tumors can have a variety of outcomes. Germinomas generally respond well to chemotherapy and radiation, and most patients are cured of this tumor. NGGCTs are more difficult to treat and many of these tumors return despite treatment.

Finding information about specific prognoses and survival rates is a personal decision. The current statistics are only summary data, and do not necessarily reflect results from new or experimental therapies. These data do not determine how individual patients might respond to their treatment – everyone is different. That said, some people may choose to look for this information, which can be found in the 2019 CBTRUS Statistical Report, in Tables 20-24.¹

References

Ostrom QT, Cioffi G, Gittleman H, et al. CBTRUS Statistical Report: Primary Brain and Other Central Nervous System Tumors Diagnosed in the United States in 2012-2016. Neuro-oncology. 2019;21(Suppl 5):v1-v100.