Pineal Region Tumors;
Pineal Cyst
The large majority of pineal gland cysts do not enlarge much if at all. However, some enlarge over time slowly.
Although a true pineal cyst is benign and usually harmless, because they can mimic a tumor, they often need to be distinguished from other cystic tumors which can occur in the region of the pineal gland.
What Types of Symptoms Are Typical?
Most pineal gland cysts are asymptomatic, meaning they do not cause any symptoms. They are occasionally found incidentally when a patient has a CT or MRI scan of the head for another reason.In those patients who have larger cysts, they can cause symptoms. Symptoms can include a condition known as hydrocephalus which is caused by the cyst compressing the cerebral aqueduct, a fluid-filled passage within the brain that is near the area of the pineal gland. By compressing the aqueduct, the normal flow of cerebrospinal fluid is blocked and pressure builds up which can lead to symptoms such as headache, nausea and vomiting, visual problems and even lethargy and coma if severe.
A large cyst can also put pressure on the brain stem adjacent to it, which can lead to visual symptoms such as paralysis of upward gaze.
How Is The Diagnosis Typically Made?
Most pineal gland cysts have a characteristic appearance on an MRI and can sometimes be distinguished from other tumors of the pineal region, such as pineoblastoma, pineocytoma and pineal germinoma. In some patients it will be recommended to follow the cyst with MRI to determine if it is growing. In those which are enlarging or cannot be distinguished from other types of tumors, a biopsy or surgical removal may be indicated to make the diagnosis.
What Are Some Common Treatments?
Because most cysts are benign and asymptomatic, most patients with an MRI which is completely consistent with a benign cyst will be recommended to do nothing at first. The cyst may be followed with occasional MRI scans to determine if it is enlarging. In cases where there is any doubt as to the actual diagnosis and in patients who are symptomatic a surgical procedure may be recommended. A biopsy to obtain a small piece of tumor for pathology or a full surgical resection to remove as much of the mass as possible are options. In patients who a pineal cyst is confirmed, often no further treatment is necessary since these lesions do not tend to recur or grow significantly.However, every patient is different and cysts can be confused with other masses that can occur in the pineal region. Therefore, each case should be discussed with the patient's own personal treating physician.
Pineal Germinoma
What Is It?
A pineal germinoma is a common type of germ cell tumor, originating from germ cells left over from embryonic development. While these germ cell tumors are common in the gonads, the ovaries in women and the testes in men, they can occur elsewhere in the body. One of the relatively common locations for this tumor type is in the pineal region of the brain. In fact, of all the tumors that occur in the pineal region, germinoma is the most common overall. They occur most commonly in young adults and children.While most of these tumors are considered malignant, they can vary somewhat in their grade and aggressiveness. While germinoma is the general name for this type of tumor, they are called dysgerminoma when they occur in the ovaries and seminoma when they occur in the testes.
The pineal gland is a small part of the brain which lies almost directly in the middle of the head. Several brain tumor types can occur in this region. In addition to a this tumor, the pineal region can be home to other germ cell tumors, teratomas, pineocytoma, pineoblastoma, and even gliomas and other types of brain tumors.
Other germ cell tumors include choriocarcinoma, yolk sac tumor, teratoma and mixed germ cell tumors. Most of these tumors can occur in the pineal region as well but are less common than germinoma.
What Types of Symptoms Are Typical?
Because the pineal gland sits just above and behind the third ventricle and the cerebral aqueduct, fluid-filled spaces in the brain, an enlarging tumor in this region can compress the aqueduct, cutting off the normal flow of fluid within the brain. This can lead to what is known as hydrocephaluswhich results in enlargement of the ventricles and increased pressure in the head. This can lead to symptoms such as headache, nausea, vomiting and finally neurological deterioration as it becomes more severe.Other symptoms which can occur due to compression of the surrounding parts of the brain include a paralysis of upward gaze of the eyes and other eye and visual symptoms (due to compression of part of the brain stem called the superior colliculi), disturbances of gait and precocious puberty in children.
How Is The Diagnosis Typically Made?
Patients who present with symptoms suggestive of a brain tumor such as a germinoma will generally undergo a thorough neurological evaluation and examination. Often, a neuroimaging study such as a CT scan or MRI scanwill be performed to detect the tumor. An MRI shows the most resolution of the tumor and surrounding normal structures.While most tumors in the region of the pineal gland can be identified readily on MRI, it is not always possible to tell what type of pineal tumor it is based solely on the imaging study. For example, it may be difficult to distinguish pineal germinomas from pineocytomas or pineoblastomas. While some of these tumors are treated solely based on the imaging findings, many tumors will require a surgical procedure to obtain tumor tissue which can be analyzed by a pathologist to make a definitive diagnosis.
In the case of pineal region tumors, some patients will undergo blood and/or cerebrospinal fluid sampling so that they can be analyzed for two compounds, beta-HCG (human chorionic gonadotropin) and AFP (alpha-feto protein). These compounds can be produced by some types of germ cell tumors. Germinoma however does not typically produce either. Additionally, the cerebrospinal fluid is sometime analyzed for cytology, meaning that it is analyzed for any tumor cells in the fluid. This can indicate spread of the tumor through the fluid to the spinal or other regions of the central nervous system.
What Are Some Common Treatments?
Some medical centers advocate treating patients who have this tumor with radiation treatments and chemotherapy alone because these tumors are typically very sensitive to these treatments. However, without a biopsy it can be hard to be 100% sure that the diagnosis is acurate. Therefore, in many cases a biopsy or full surgical resection is recommended to obtain tumor tissue for analysis. If the pathologist confirms that it is germinoma, most patients will undergo radiation treatment and/or chemotherapy. If another tumor type is present then surgery to remove as much tumor as possible is usually attempted.Each patient is different and therefore treatment plans should be discussed with each patient's own treating physicians.
Pineoblastoma
What Is It?
A pineoblastoma is a rare malignant brain tumor which arises from the cells of the pineal gland which sits near the center of the head and brain. They are a form of primitive or undifferentiated tumor which displays pathology which is very abnormal, quickly growing and invasive.While other types of tumors are more common in the region of the pineal gland, such as a pineal germinoma, a pineoblastoma is one of the more malignant tumors found in this area. These high-grade tumors are related to and on a spectrum with more benign variants which are called pineocytoma, pinealocytoma or pinealoma (all different names for the same benign tumor).
What Types of Symptoms Are Typical?
Because the pineal gland sits just above and behind the third ventricle and the cerebral aqueduct, fluid-filled spaces in the brain, an enlarging tumor in this region can compress the aqueduct, cutting off the normal flow of fluid within the brain. This can lead to what is known as hydrocephaluswhich results in enlargement of the ventricles and increased pressure in the head. This can lead to symptoms such as headache, nausea, vomiting and finally neurological deterioration as it becomes more severe.Other symptoms which can occur due to compression of the surrounding parts of the brain include a paralysis of upward gaze of the eyes and other eye and visual symptoms (due to compression of part of the brain stem called the superior colliculi), disturbances of gait and precocious puberty in children.
How Is The Diagnosis Typically Made?
Patients who present with symptoms suggestive of a brain tumor such as a pineoblastoma will generally undergo a thorough neurological evaluation and examination. Often, a neuroimaging study such as a CT scan or MRI scan will be performed to detect the tumor. An MRI shows the most resolution of the tumor and surrounding normal structures.While most tumors in the region of the pineal gland can be identified readily on MRI, it is not always possible to tell what time of pineal tumor it is based solely on the imaging study. For example, it may be difficult to distinguish a pineoblastoma from a pineocytoma or a pineal germinoma. While some germinomas are treated solely based on the imaging findings, many tumors will require a surgical procedure to obtain tumor tissue which can be analyzed by a pathologist to make a definitive diagnosis.
In the case of pineal region tumors, some patients will undergo blood and/or cerebrospinal fluid sampling so that they can be analyzed for two compounds, beta-HCG (human chorionic gonadotropin) and AFP (alpha-feto protein). These compounds can be produced by some types of germ cell tumors. Pineoblastoma however does not produce either. Additionally, the cerebrospinal fluid is sometime analyzed for cytology, meaning that it is analyzed for any tumor cells in the fluid. This can indicate spread of the tumor through the fluid to the spinal or other regions of the central nervous system.
What Are Some Common Treatments?
Treatment for pineoblastoma varies from patient to patient depending on specifics of each case such as age, tumor size and presenting symptoms. While other pineal tumors such as germinoma are very sensitive to radiation, surgical removal of pineoblastomas is often preferable. The aim of surgery can be to both obtain tumor tissue to analyze to make a definitive diagnosis and to remove as much of the tumor as possible. Various approaches to the pineal region can be used by neurosurgeons. In general, the procedures require a craniotomy (opening of the skull) in the posterior part of the head and is directed either above the cerebellum or between the occipital hemispheres to reach the pineal region.Some patients will undergo other treatments such as radiation treatments for residual tumor or chemotherapy, particular in these malignant tumors.
Because the appropriate treatment varies considerably from patient to patient, each case should be evaluated and discussed with the patient's own treating physicians.
Pineocytoma
What Is It?
A pineocytoma, also known as a pinealocytoma or pinealoma, is a rare benign tumor of the pineal gland of the brain. This brain tumor arises from the cells of the pineal itself. Since pinealocytoma is rare, other types of tumors are more common in the pineal region, such as apineal germinoma or even a glioma. There is usually no known cause for pineal tumors.The pineal sits near the center of the brain between the two hemispheres of the brain, behind the thalamus and third ventricle, one of the fluid-filled spaces in the brain, and just above the posterior midbrain.
Most pineocytomas are considered low-grade or benign tumors. However, tumors of the pineal gland itself can very in aggressiveness with high-grade or malignant variants also occurring. These high-grade variants are termed pineoblastoma and display much more primitive or undifferentiated pathology.
What Types of Symptoms Are Typical?
The pineal gland sits behind the third ventricle, a fluid-filled space in the brain, and near the cerebral aqueduct, a narrow passage through which the cerebrospinal fluid passes. For this reason, as a pineal tumor, such as a pineocytoma, enlarges it can compress the aqueduct and block the normal flow of cerebrospinal fluid. This can lead to a condition known ashydrocephalus which results in enlargement of the ventricles and increased pressure in the head. This can lead to symptoms such as headache, nausea, vomiting and finally neurological deterioration as it becomes more severe.Other symptoms which can occur in some patients include a paralysis of upward gaze of the eyes (due to compression of part of the brain stem called the superior colliculi), disturbances of gait and precocious puberty in children.
How Is The Diagnosis Typically Made?
In a patient who presents with symptoms suggestive of a pineocytoma, a thorough neurological evaluation usually includes a neuro exam and a neuroimaging study such as a CT scan or MRI scan. A contrast MRI scan is the most preferred study to clearly define the tumor and its relationship to surrounding structures.While an MRI can identify most tumors and indicate their location in the region of the pineal gland, in most patients the type of tumor cannot be identified definitively without a biopsy of tumor tissue to be evaluated by a pathologist. Pineocytoma is a relatively rare tumor of the pineal region and therefore is often not diagnosed until a surgical procedure can obtain tumor tissue for analysis.
In the case of pineal region tumors, some patients will undergo blood and/or cerebrospinal fluid sampling so that they can be analyzed for two compounds, beta-HCG (human chorionic gonadotropin) and AFP (alpha-feto protein). These compounds can be produced by some types of germ cell tumors. Pineocytoma however does not produce either.
What Are Some Common Treatments?
Treatment for pinealoma varies from patient to patient depending on specifics of each case such as age, tumor size and presenting symptoms. While other pineal tumors such as germinoma are very sensitive to radiation, surgical removal of pineocytomas is often preferable. The aim of surgery can be to both obtain tumor tissue to analyze to make a definitive diagnosis and to remove as much of the tumor as possible. Various approaches to the pineal region can be used by neurosurgeons. In general, the procedures require a craniotomy (opening of the skull) in the posterior part of the head and is directed either above the cerebellum or between the occipital hemispheres to reach the pineal region.Some patients will undergo other treatments such as radiation treatments for residual tumor or chemotherapy, particular in more malignant tumors.
Because the appropriate treatment varies considerably from patient to patient, each case should be evaluated and discussed with the patient's own treating physicians.
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