Extra-Axial Tumors:
Arachnoid Cyst
What Is It?
An arachnoid cyst is a fluid-filled cyst that that occurs in the arachnoid membrane around the brain. While completely benign, and not a tumor per se, they can cause symptoms by compression of adjacent nervous system structures.The arachnoid membrane is a thin, filmy tissue that is one of the three coverings of the brain, the meninges. It normally encloses the subarachnoid space, which is filled with cerebrospinal fluid, a water-like fluid that surrounds the brain and spinal cord. It is thought that during development in some cases the arachnoid does not form properly so that a sack, or cyst, is formed which lets fluid into it but not out. This can lead to the cyst enlarging and the adjacent brain under-developing. Therefore, these cysts are not literally brain tumors, they are really congenital (you are born with it) malformations of the arachnoid.
Arachnoid takes its name because the membrane somewhat resembles a spider web.
The cyst wall is basically just arachnoid membrane and the cyst is filled with fluid which is essentially the same as cerebrospinal fluid.
Some cysts do not appear to change in size while others can grow over time, compression adjacent neurological structures.
An arachnoid cyst can occur in many parts of the central nervous system, including the temporal area, the suprasellar area (above the pituitary gland), the cerebellopontine angle (between the brainstem and cerebellum) and the spinal canal.
What Types of Symptoms Are Typical?
The symptoms associated with an arachnoid cyst varies depending on its location and size. Many cysts are completely asymptomatic and others have non-specific symptoms like headache.In the cyst is symptomatic, it can cause neurological symptoms related to its location, which varies. Some possible symptoms include seizures, hydrocephalus, developmental delay, behavioral changes, and weakness of part of the body. Many others are possible and vary from patient to patient.
In young children, a large cyst can cause deformation of the shape of the head.
How Is The Diagnosis Typically Made?
Because many cysts do not cause any symptoms, the diagnosis is often made incidentally when the patient has a head CT scan or MRI scan for another reason. In symtpomatic cases, after a neurological evaluation, a CT or MRI scan is also typically done to determine the cause. On these imaging studies the cysts have a characteristic appearance and the fluid filling them looks essentially the same as cerebrospinal fluid. One other pathology which can sometimes be confused for an arachnoid cyst is anepidermoid cyst, which is a benign congenital tumor. However, these tumors can usually be distinguished from an arachnoid cyst with specific MRI techniques.What Are Some Common Treatments?
The treatment for a cyst varies from patient to patient. Complete surgical removal of the cyst is often impossible because its fine capsule is adherent to many neurological structures. However, some common approaches are listed here:Asymptomatic cysts are often not treated, simply watched and then treated later if they enlarge or begin causing symptoms. This is up to the discretion of the patient and treating physician.
Simple drainage of the cyst through a needle or a small hole in the skull is generally not effective. In most cases this leads to immediate re-filling of the cyst.
Fenestration is a term which basically means making windows into the cyst. In this surgical procedure, holes are made into the cyst on as many sides as possible. If possible, some of the capsule is removed. This allows a free flow of fluid into and out of the cyst with the goal of preventing the cyst to close off and not let fluid out. This can help to prevent future growth of the cyst.
Some physicians recommend a shunt procedure which places a catheter into the cyst. The other end of the catheter can go into another compartment in the body where the fluid can be re-absorbed easily. Most commonly this is the abdominal cavity. The goal of these procedures is to divert the fluid away from the cyst so that it does not grow or cause pressure on neurological structures.
Each case is different, so each patient should discuss their treatment options and plan with their own physician.
Chordoma
What Is It?
A chordoma is a rare tumor that is derived from primitive remnants of a developmental structure called the notochord. The notochord is present during early development and helps to guide the development of the nervous system and vertebral column in vertebrates. Rarely, remnants of this structure, which normally is not present in the body after early development, can give rise to this slow-growing tumor.Chordomas can occur anywhere along the vertebral column and base of the skull. However, the two most common locations by far are the sacrum (the bottom part of the spinal column and a part of the pelvis) and the clivus. The clivus is a bone of the skull, located at the base of the skull just in front of the brain stem and just behind the nasal cavities. Therefore, while not technically a brain tumor, clival chordomas (the ones originating in the clivus) grow very close to the brain stem and the cranial nerves that pass through the area. Because of its location at the base of the skull, this is one of many tumors which are often called skull base tumors.
While the pathology of these rare tumors are generally relatively benign, they can be quite aggressive with destruction of local tissues. The erode the bone and adjacent soft tissues and can cause damage to the nerves and brain stem as they enlarge.
What Types of Symptoms Are Typical?
Sacral chordomas often cause back pain and/or neurological symptoms such as leg pain and weakness.Clival chordomas sit in a region which can affect both the nerves coming out of the brain stem, the cranial nerves, and the brain stem itself. While presentation can vary, common presenting symptoms include double vision (due to disruption of the nerves that control eye movements), dysfunction of eye movements, and headache.
As they enlarge, other cranial nerves can become involved, often causing numbness or tingling of the face. Very large tumors can compress the brain stem, leading to more severe neurological impairment.
How Is The Diagnosis Typically Made?
After a consistent history and physical, most brain tumors require a CT scan or MRI scan to image the brain and surrounding structures. The typical location in the clivus and other factors make this tumor fairly easy to diagnose by these studies. However, as with any tumor, obtaining a tissue sample for pathological analysis is needed to make a definitive diagnosis and to distinguish it from other tumors that can occur in the area, such as skull base chondrosarcoma.What Are Some Common Treatments?
Although each case is different, many chordoma patients are recommended to have surgery. This is done through a number of different types of skull base approaches, including endonasal transsphenoidal surgery in some centers. How much tumor can be removed depends on the size and invasiveness of the tumor. Because these tumors do tend to recur frequently, the more tumor that can be removed safely, the better chance for longer intervals until the tumor recurs. If residual tumor is left after surgery, radiation treatments are often recommended to help slow or prevent these recurrences. Each specific case is different and should be discussed with each patient's physician to decide what treatment options are best.Craniopharyngioma
What Is It?
A craniopharyngioma is a tumor which occurs in the region of the pituitary gland at the base of the brain. It is thought to arise from remnants of embryonic development which are important in the formation of the pituitary gland. These tumors tend to be slow growing but locally destructive. They very frequently contain areas of calcification as well as cystic areas which are filled with fluid. They can vary from predominantly solid to predominantly cystic and everything in between.Craniopharyngiomas occur both in children and adults, with peaks in both children and in older adults. They generally occur in the region of the pituitary gland, known as the sella turcica, or simply sella. Commonly, they are largely in the supra-sellar region and can expand upward into the base of the brain in an area known as the hypothalamus. The optic nerves, the nerves carrying visual information from the eyes, are also in this region.
What Types of Symptoms Are Typical?
Craniopharyngiomas tend to grow slowly and thus their symptoms usually develop slowly over years. General symptoms such as headache are common but because of their location, craniopharyngiomas also commonly involve the pituitary gland, hypothalamus and the optic nerves. The pituitary gland and hypothalamus are important for several hormonal functions and autonomic function. Therefore, damage to them can lead to several hormonal syndromes.Examples of these hormonal insufficiencies are growth hormone insufficiency (growth failure in young patients), adrenal insufficiency (hypotension, hypoglycemia, lethargy, confusion, etc.), hypothyroidism (weight gain, fatigue, cold intolerance), and diabetes insipidus (excessive fluid intake and urination). Many patients also have reproductive dysfunction including impotence in men and loss of normal menstrual cycles in women. Young patients can have delayed puberty.
Injury to the optic nerves from the eyes can frequently lead to various degrees of visual loss. Larger tumors can have more of an impact on the hypothalamus and brain which can lead to vague endocrine, autonomic and behavioral manifestations.
Occasionally larger tumors which are located superiorly in the 3rd ventricle, a fluid-filled space in the brain, can lead to hydrocephalus.
How Is The Diagnosis Typically Made?
After a thorough neurological examination, most patients get an imaging study such as a CT scan or MRI scan. An MRI typically demonstrates a typical appearance in the sellar and supra-sellar regions. While the appearance of craniopharyngioma is fairly unique, it must be distinguished from other brain tumors which can occur in the same region, such as a pituitary adenoma, Rathke's cleft cyst or meningioma. A definitive diagnosis requires a sample of tumor tissue to be analyzed by a pathologist.In addition to these imaging studies, most patients with a tumor in this location will require an extensive hormonal work-up, often by an endocrinologist. This includes blood testing of several pituitary hormones and other related hormones. This helps to diagnose any hormonal insufficiencies which may be caused by the tumors compression or destruction of the pituitary gland, stalk or the hypothalamus.
Most patients will also undergo a detailed ophthalmologic evaluation to determine if there is any visual dysfunction.
What Are Some Common Treatments?
The primary medical treatments that many patients with craniopharyngioma will undergo is hormonal replacement therapy for those patients with abnormal hormonal function. This is not aimed at treating the tumor itself but rather is used to replace hormonal function which has been damaged by the tumor.To treat the tumor itself, most patients will be recommended for surgery to remove as much of the tumor as possible. While total removal is ideal in terms of long term control of the tumor, this is often not possible because of the complex anatomy of the region. Overly aggressive surgery can result in worsening of vision, hormonal function and other neurological disability. Very large tumors that cannot be removed completely and cystic tumors very commonly recur even after multiple procedures. However, this is quite variable.
Surgery is either accomplished through a craniotomy (an opening through the skull) or through the nose in what is called a transsphenoidal approach, or both. Which is appropriate varies depending on the patient and the specific tumor characteristics.
Some tumors that can't be removed completely will undergo radiation treatments to try to control the residual tumor.
Because these are complex tumors, their treatment varies considerably from one patient to another. Each patient should discuss their treatment options with their own physicians.
Dermoid Cyst
What Is It?
A dermoid cyst is generally a benign tumor which arises from ectodermal tissue during development. Ectodermal tissue are cells that give rise to the linings of the body, most notably the skin and all its appendages (hair follicles and hair, sweat glands, teeth, etc.). While the nomenclature sometimes gets confused, a dermoid is essentially a type of teratoma which only includes epidermal and dermal components.While these can occur in many parts of the body, we will focus on nervous system dermoids here. During development, these primitive tissues can accidentally get trapped within the developing nervous system. Although these cystic tumors are present from birth (they are congenital) they do not always present in childhood. Because they tend to be slow growing, they can take many years before they reach a size that begins to cause symptoms.
These brain tumors have a thick cyst wall and inside are the cells that resemble those of epithelial and dermal tissues of the skin. This can include several types of tissue, most notably sweat glands, skin-like cells and hair follicles that produce hair. Therefore, a dermoid cyst typically has debris inside which can include hair and teeth as well as oily, fatty, waxy material which has been secreted and/or sloughed off into the interior of the cyst. These can occur in several areas in the central nervous system including the spinal canal and the suprasellar area (above the pituitary gland).
What Types of Symptoms Are Typical?
The symptoms associated with a dermoid cyst vary depend on its size and location. As they enlarge they can compress neurological structures, leading to neurological symptoms. These symptoms are entirely dependent on the location, but can include numbness or weakness in a part of the body, hearing or visual difficulties, as well as other nervous system deficits.How Is The Diagnosis Typically Made?
After an in depth neurological examination, typically a CT scan or MRI scanof the brain or spine will reveal the cystic mass. While the appearance of these tumors is fairly characteristic, it can be confused for some other types of tumors. It should be distinguished from an epidermoid cyst, which is a similar cyst but which only contains epithelial tissue and therefore does not have fat, hair, teeth or other such tissues inside them.As with other tumors, to make a definitive diagnosis, tumor tissue is required to be analyzed by a pathologist.
What Are Some Common Treatments?
Treatment of these tumors depends on the specifics of each case. However, generally, for symptomatic cysts, surgical removal is often required. The goal of surgery is complete removal of the cyst and its contents but this is not always possible. If the cyst wall is adherent to important structures of the nervous system, removing them may be dangerous in some cases. In these cases, small parts of the tumor may be left behind.Epidermoid Cyst
What Is It?
An epidermoid cyst is typically a benign brain tumor that arises from abnormal cells being left in the nervous system during development. Ectodermal cells that normally form skin are trapped in the developing nervous system, creating a cyst which is lined inside with ectodermal cells. In other words, there are skin-like cells lining the inside of the cyst. This lining grows and sloughs much like skin does, but because it is towards the inside of the cyst, the sloughed cells stay inside the cyst and expand the cyst. Therefore, these cysts glow slowly and are filled with a flaky material.Epidermoid cyst can occur in many parts of the body, but in the central nervous system, they most frequently occur in the space between the brain stem and cerebellum (called the cerebellopontine angle or CP angle), above the pituitary gland or near the temporal lobe of the brain. The CP angle is the most common site in the nervous system.
Although these tumors are congenital (present at birth), they typically do not present until older age (20 - 40 years old on average) because they take a long time to expand to a size that causes symptoms.
Epidermoids are related to, but different from, dermoid cysts. In the later, the abnormal ectodermal cells differentiate more into skin forming tissues which include both epidermal and dermal elements, so that these tumors typically have sweat glands, hair follicles and other dermal appendages.
What Types of Symptoms Are Typical?
The presentation and clinical symptoms of these tumors vary depending on size and location. In the CP angle, they tend to cause headache, double vision (diplopia), gait disturbances, and/or facial pain or numbness. These symptoms and others will vary from patient to patient.How Is The Diagnosis Typically Made?
As with most tumors, after a neurological examination, a CT scan or MRI scan is needed to detect the tumor. Typically, tumors require a sample of tumor tissue to make the definitive diagnosis by pathological examination.In the case of epidermoid cyst, the appearance on MRI is fairly characteristic. However, they can appear very similar to another type of mass called an arachnoid cyst. Some special MRI sequences (a diffusion weighted image or DWI) can help to distinguish these two diagnoses. Definitive diagnosis generally does require tumor tissue however.
What Are Some Common Treatments?
As with all tumors of the central nervous system, treatment decisions vary greatly depending on the patient and the specifics of each case. However, generally, epidermoid cysts that are causing symptoms are generally recommended to be treated. Treatment usually consists of a surgical resection of the tumor. The goal is total removal of the tumor but due to their cystic nature, they can be difficult to remove in their entirety, particularly if parts of the cyst wall are adherent to important structures such as nerves or the brainstem. While these are generally benign tumors, they can continue to enlarge slowly and recur after surgery if any of the cyst wall was not removed.Meningioma
What Is It?
A meningioma is one of the most common primary brain tumors. It is almost always a benign tumor that arises from cells of the arachnoid membrane.The arachnoid membrane is one of the three layers covering the brain and spinal cord. It is a thin, filmy, spider web-like tissue (hence the name arachnoid, or "spider web-like"). Therefore, these tumors actually arise outside the brain itself, but because of their close proximity to nervous system structures, they are often touching or pushing into parts of the brain or spinal cord. They can occur anywhere where arachnoid is found, throughout the intracranial compartment and the spinal column. Rarely they can be found inside the cerebral ventricles, the fluid spaces within the brain.
While the large majority of meningiomas are benign and very slow growing, rarely they can have more malignant pathology and therefore act more aggressively and invasively.
Most meningiomas are named for their site of origin. For example, they can be classified as convexity, parafalcine, skull base, olfactory grove, tuberculum sellae, dorsum sella, clival, petrosal, cerebellopontine, foramen magnum or spinal, to name a few, all referring to various anatomical locations around the central nervous system.
What Types of Symptoms Are Typical?
When small, most meningioma are asymptomatic. Depending on their location, as they enlarge, they can start to invade or cause compression of neurological structures. As this happens, symptoms related to that neurological structure can occur. Typically this progression is slow as most of these tumors grow slowly over years or decades.Neurological symptoms depend completely on the location of the tumor. Large convexity tumors may cause weakness or sensory symptoms on the opposite side of the body. Large frontal or temporal tumors sometimes cause psychological disturbances, including personality changes. Tumors of the skull base can affect the function of cranial nerves, producing problems with smell, vision, hearing and balance, facial movement, facial sensation, swallowing, and eye movements, to name just a few possibilities.
In addition to these symptoms which are specific to the location of a given tumor, headache is a common finding in many of these patients. Seizure can also occur, particularly with tumors that compress parts of the cerebral cortex.
How Is The Diagnosis Typically Made?
After presenting for a neurological examination, generally a CT scan or MRI scan will reveal the tumor. Meningiomas have a very characteristic appearance but they can be mistaken for other tumors depending on their location. Therefore, like most other tumors, a piece of tumor tissue is needed to make a definitive diagnosis. This is usually accomplished through surgery or a biopsy.What Are Some Common Treatments?
The treatment plan for these tumors varies considerably from patient to patient, depending on symptoms, and location and size of the tumor. Asymptomatic tumors may be watched closely unless the patient prefers early surgery. In the case of symptomatic tumors, surgery to remove or de-bulk the tumor is often recommended. The specific surgical approach varies depending on the tumor size and location. The goal of surgery is to remove the entire tumor, which gives the best chance for a cure or long-term control. However, in some locations complete removal is not possible or risky and therefore some tumor is left.Radiation treatments, particularly focused beam radiation or stereotactic radiation treatments, are also sometimes used. They are often effective at slowing or stopping the growth of the tumor, although some continue to grow or do not decrease in size. This is frequently used for any residual tumor which is left after surgery to delay or prevent its re-growth.
As with all medical conditions, the appropriate treatment plan varies from patient to patient dependent on many factors. Each patient should discus their individual case and their options with their physician team.
Pituitary Adenoma
What Is It?
A pituitary adenoma is a benign tumor of the anterior pituitary gland. It is the most common pituitary tumor of the gland itself. Adenoma is a general term for a benign tumor of a secreting tissue. There is no known cause in most cases of these pituitary tumors.The pituitary gland is a small structure that lies at the base of the brain. It works closely with the brain to aid in coordination of many aspects of endocrine (hormonal) function. It is vital to the normal functioning of metabolism and other glands such as the thyroid, adrenals, mammary, testes and ovaries and even aspects of kidney function. It is comprised of an anterior pituitary (known as the adenohypophysis) as well as a posterior pituitary (called the neurohypophysis). Pituitary adenomas always arise from the anterior part.
Pituitary adenomas vary greatly from one to the next. While many are simply a mass which grows in the pituitary, several types actually secrete pituitary hormones. Rather than secreting these hormones in a normal manner, they over secrete them so that there is an over abundance of that hormone in the body. This abnormal secretion can lead to very specific clinical syndromes related to that hormone. These syndromes are described briefly below but each have a separate page to describe them in more detail.
- Prolactinoma: A pituitary tumor which secretes the hormone prolactin.
- Growth Hormone Secreting Adenoma: A pituitary adenoma which secretes growth hormone. This can lead to the syndromes of Acromegaly andGigantism.
- Cushing's Disease: A pituitary adenoma which secretes the hormone adrenocorticotropic hormone (ACTH) which stimulates the adrenal gland to secrete cortisol.
- Nonsecreting Pituitary Adenoma (Endocrine Inactive Adenoma): A pituitary tumor which does not directly secrete any hormones.
- Pituitary tumors which secrete the other anterior pituitary hormones, thyroid stimulating hormone (TSH), leutinizing hormone (LH), and follicle stimulating hormone (FSH), are all very rare. TSH secreting tumors can lead to hyperthyroidism or over secretion of thyroid hormone from the thyroid gland. Secretion of either FSH or LH can lead to loss of normal menstrual cycles and infertility in women as well as impotence and infertility in men.
In addition to the secretion of hormones, as a pituitary adenoma grows it can cause damage to the normal pituitary gland adjacent to it so that the patient may develop pituitary insufficiency of one or more hormone. Finally, with any pituitary tumor, increased secretion of prolactin (hyperprolactinemia), a hormone important for the development of breast tissue (the mammary glands), can lead to abnormal menses in women or impotence in men.
What Types of Symptoms Are Typical?
Presenting symptoms of pituitary tumors vary depending on the type of the tumor and its size.Headaches: Any pituitary tumor can present with headaches.
Visual Loss: Any pituitary tumor which is large enough can cause compression of a part of the visual system in the brain which runs just above the pituitary gland. This compression can lead to loss of normal visual function which usually presents initially with loss of peripheral vision in both eyes (called homonymous hemianopsia). Some loss of visual acuity can occur as well and very large tumors that go untreated or expand quickly can lead to complete blindness. Some of this visual loss can be reversible with treatment of the tumor in some cases.
Hyperprolactinemia: Any pituitary tumor that gets big enough can interfere with the normal secretion of the hormone called prolactin. This leads to an increase in secretion of the hormone, although it does not typically get as high as from a secreting prolactinoma. This elevated prolactin can be asymptomatic but it can also cause abnormal reproductive function including loss of normal menstrual cycles in women and impotence in men. It can also lead to breast development and secretion of a milk-like substance from both men and women.
Hormone Syndromes: If a pituitary tumor secretes a hormone, additional symptoms related to that hormone can occur. For a more thorough description of those clinical syndromes, see the pages for acromegaly,gigantism, prolactinoma, and Cushing's disease.
Rarely, a pituitary adenoma can bleed suddenly (called pituitary apoplexy), causing a sudden enlargement in its size. This often leads to acute pituitary dysfunction as well as sudden loss of vision. This is generally considered a surgical emergency and most often leads to an emergent operation to remove the tumor and blood.
How Is The Diagnosis Typically Made?
Patients present in various ways, depending on the type of tumor they have. However, after a neurological evaluation, a CT scan or MRI scan are usually ordered to detect the tumor. The appearance of a pituitary adenoma is generally regular enough to make the diagnosis with a good degree of accuracy just based on the MRI alone. However, some related tumors can be mistaken for a pituitary tumor. Some examples of these areRathke's cleft cyst, craniopharyngioma, meningiomas of the tuberculum sellae and diaphragma sellae.To confirm the diagnosis, tumor tissue needs to be assessed by a pathologist in most cases.
In addition the the imaging studies described above, patients with pituitary tumors will usually undergo blood tests to assess their hormonal function. The purpose of these tests is to both look for any oversecretion of hormones associated with the tumor as well as to determine if the patient has any impaired function of normal pituitary gland function. In the case ofCushing's disease, some patients will undergo inferior petrosal sinus sampling (a special blood test done by a radiologist) to confirm and refine the diagnosis.
What Are Some Common Treatments?
The majority of pituitary adenomas, particularly if the patient has symptoms, are treated by surgery. In most cases this involves a procedure called the transsphenoidal approach. This approach, through the nasal passages, is the most direct route to the area of the pituitary gland and is generally better tolerated with a quicker recovery than a craniotomy (opening the skull).In patients who have loss of some normal pituitary function, they may require hormonal replacement therapy to prevent symptoms. For example, if the patient presents with low thyroid hormone, they may require treatment with synthetic thyroid hormone.
In a few cases of tumors which secrete hormones, medical therapy to control the tumor may be attempted. The most commonly used example of this is using drugs called dopamine agonists (bromocriptine and cabergoline are the most commonly used examples) in patients with prolactinoma. In some cases, this hormone will inhibit the tumor and can even cause the tumor to shrink on its own, preventing or delaying the need for surgery.
Each tumor and patient is different, so it is hard and inappropriate to make generalizations about what treatment plan is most appropriate. Each patient should discuss their options with their own physician team.
Acromegaly
What Is It?
Acromegaly is a syndrome caused by excessive secretion of growth hormone from a pituitary adenoma, a benign pituitary tumor. The high levels of growth hormone lead to a characteristic appearance with thickened, coarse facial features and large hands and feet.As opposed to pituitary gigantism, acromegaly occurs in adults after their growth plates have closed in their long bones. Therefore, the height of the individual does not change, their tissues and bones simply get thicker and coarser. The syndrome can also lead to other metabolic and physiologic changes which can cause long-term health problems.
Many famous people have suffered from gigantism and/or acromegaly. A couple notable examples are Andre the Giant and Richard Kiel ("Jaws" in the James Bond movies).
What Types of Symptoms Are Typical?
All pituitary tumors can lead to general symptoms like headache, vision changes due to compression of the optic chiasm and loss of normal pituitary function.In the case of acromegaly, the pituitary tumor secretes growth hormone which causes several changes to metabolism and growth. Most notably, patients slowly develop soft tissue swelling of the hands, feet, nose, lips, ears and general thickening of the skin. Parts of the skull and jaw are enlarged with a protruded brow and jaw. This characteristic appearance occurs slowly, usually over years or even decades, so that sometimes the patient is not aware of it until they compare their appearance to earlier photos.
In addition to the externally visible features, internal changes occur as well. These can include enlargement of the heart, arthritis, carpal tunnel syndrome, high blood pressure, diabetes mellitus, and heart and kidney failure. Left untreated the high blood pressure, diabetes and heart enlargement can lead to significant cardiac and vascular disease which can be a major source of illness and even death.
How Is The Diagnosis Typically Made?
As with other pituitary adenomas, a neurological evaluation typically includes a CT scan and/or MRI scan to detect the tumor.Blood testing to evaluate the pituitary hormones will demonstrate high levels of growth hormone. They will also demonstrate high levels of insulin-like growth factor (IGF-1) which is increased with increased GH levels.
What Are Some Common Treatments?
As with other pathologies, each tumor and patient is different, so it is hard and inappropriate to make generalizations about what treatment plan is most appropriate. Each patient should discuss their options with their own physician team.
However, most patients with acromegaly will require an operation to remove the tumor to lower the levels of growth hormone and prevent the long-term heart and kidney complications of the disease. As with other pituitary adenomas, this is usually accomplished through a transsphenoidal procedure through the nasal passages.
Some patients with a growth hormone secreting tumor will undergo medical treatment with a dopamine agonist or somatostatin agonist drug. These drugs are effective in controlling the tumor and secretion of growth hormone only in a small subset of patients.
Cushings Disease
What Is It?
Cushings disease is caused by a pituitary adenoma (a benign pituitary tumor) which secretes adrenocorticotropic hormone (ACTH). Cushing's disease is named for Harvey Cushing, considered to be the father of modern neurosurgery.ACTH is a hormone that normally stimulates the cortex of the adrenal glands to secrete its hormones, predominately cortisol. Cortisol has effects on many different aspects of metabolism but is particularly important for the stress response. It is secreted in times of stress and increases blood pressure and blood sugar, amongst other metabolic effects.
With an ACTH secreting adenoma, the adrenal gland is over-stimulated and very high levels of cortisol occur.
Do not confuse Cushings disease with Cushing's syndrome, which is the general name for the set of symptoms seen with excess levels of cortisol from any cause (not necessarily a pituitary adenoma secreting ACTH).
What Types of Symptoms Are Typical?
High levels of cortisol have many effects. High blood pressure and high blood sugar (diabetes mellitus) are common. In addition, over time the metabolic changes lead to characteristic changes in the body. For example, weight gain is common. The weight gain is mostly central (central obesity) with sparing of the arms and legs. There is also fat deposition in the face, leading to what is called "moon facies", and in the back of the neck, called a "buffalo hump". Skin growth and wound healing is also impaired and can lead to stretch marks, or "striae". Some patients experience various psychological disturbances. Many other effects are also possible and in the long-term, untreated patients may develop significant heart disease, opportunistic infections, diabetes and other problems.In addition to this syndrome, termed Cushing's syndrome, patients with larger ACTH-secreting tumors can have any of the symptoms associated with other pituitary tumors, including headache, visual changes and hypopituitarism of other hormones.
How Is The Diagnosis Typically Made?
Like other brain tumors, a CT scan or MRI scan is often used to detect the tumor. In the case of Cushing's disease, occasionally the tumor is very small and cannot be seen adequately.As with other pituitary adenomas, blood tests are used to evaluate the pituitary hormones. In the case of Cushings disease, particularly in those patients with very small tumors which cannot be adequately seen on MRI, a special procedure called inferior petrosal sinus sampling is occasionally used. In some cases, this procedure helps to confirm that the excess ACTH is coming from the pituitary and may help to localize the tumor to one side or the other. It is performed by placing a small catheter into a vein-like structure, called the inferior petrosal sinus, which drains some of the blood coming from the region of the pituitary gland.
What Are Some Common Treatments?
The most common treatment for Cushings disease is surgical removal of the tumor through a transsphenoidal operation. When the tumor is small and cannot be easily seen this can be difficult to obtain a complete cure. In rare cases part or all of the pituitary gland is removed. In extreme cases where cortisol levels remain high despite multiple attempts to remove the tumor, both adrenal glands are removed to prevent the long-term complications and morbidity of untreated Cushing's syndrome. In the case of pituitary gland removal and/or adrenal gland removal, life-long hormonal replacement therapy is required.
As with other pathologies, each tumor and patient is different, so it is hard and inappropriate to make generalizations about what treatment plan is most appropriate. Each patient should discuss their options with their own physician team.
Nonsecreting Pituitary Tumor
What Is It?
A nonsecreting pituitary tumor is a pituitary adenomawhich does not actively secrete any hormone. Like other pituitary adenomas, it is a benign tumor arising in the anterior pituitary gland.What Types of Symptoms Are Typical?
While a nonsecreting tumor does not have a specific syndrome associated with secretion of a hormone, it can lead to loss of normal hormonal function of one or more of the pituitary hormones. Additionally, as it enlarges, it can lead to compression of the optic chiasm, a part of the visual system in the brain which leads to loss of normal vision. Headaches are also common.How Is The Diagnosis Typically Made?
The diagnosis of a nonsecreting tumor is made in the same way as any pituitary adenoma. Hormonal testing will confirm that no pituitary hormone is being secreted in excess (with the possible exception of moderately elevated levels of prolactin).What Are Some Common Treatments?
Treatments vary from patient to patient but generally include transsphenoidal surgery for patients with symptomatic tumors and hormonal replacement for patients with any loss of pituitary function. See the treatments for pituitary adenomas.Pituitary Gigantism
What Is It?
Gigantism is the name for the clinical syndrome which arises from a growth hormone secreting pituitary tumor in childhood. This is caused by a pituitary adenomawhich secretes high levels of growth hormone. However, the term itself can be used to describe other forms and causes of exceptional stature besides pituitary causes.Growth hormone is important for many aspects of development and metabolism. In early development it causes profound growth of long bones and is responsible in part for normal stature. Therefore, if a child who is still growing is exposed to higher than normal levels of growth hormone, as in the case of this syndrome, they will grow to an abnormally tall stature. These individuals are sometimes referred to as pituitary giants.
Gigantism is the unique situation in which a growth hormone secreting adenoma occurs before an individual stops growing. After the end of growth, when the "growth plates" in the long bones fuse, increase in height is no longer possible. If a tumor such as this occurs after this point, in adult life, the patient will not grow in height but bones and features may become thickened and coarse. This syndrome, although caused by the same type of tumor just at a different point in life, is calledAcromegaly.
Many famous people have suffered from gigantism and/or acromegaly. A couple notable examples are Andre the Giant and Richard Kiel ("Jaws" in the James Bond movies).
What Types of Symptoms Are Typical?
In addition to symptoms which may present with any pituitary tumor, such as headache, loss of visual function and hypopituitarism, patients with excess growth hormone secretion experience profound growth in stature. In addition, growth hormone can cause other metabolic and physiologic changes such as high blood glucose (diabetes mellitus) and high blood pressure.How Is The Diagnosis Typically Made?
As with other pituitary adenomas the diagnosis is made through imaging studies such as an MRI scan as well as blood testing to evaluate pituitary hormonal function. These tests will reveal very high levels of growth hormone as well as its downstream hormone, insulin-like growth factor (IGF-1).What Are Some Common Treatments?
For the most part, the mainstay of treatment for pituitary tumors is transsphenoidal surgery to remove the tumor. In the case of growth hormone secreting tumors, a couple of drugs are occasionally used in some patients. These include the dopamine agonists (bromocriptine) and somatostatin agonists (octreotide and lanreotide). While these may show some anti-tumor effects in some patients, they are not effective for everyone.Each tumor and patient is different, so it is hard and inappropriate to make generalizations about what treatment plan is most appropriate. Each patient should discuss their options with their own physician team. See the pituitary adenoma page for more general information about tumors of the pituitary gland.
Prolactinoma
What Is It?
Prolactinoma is a pituitary adenoma which secretes prolactin. Pituitary adenomas are benign tumors that arise from the anterior pituitary gland.Prolactin is a hormone which is important for development of mammary gland tissue and secretion of milk in lactating women. At the same time it causes inhibition of the menstrual cycle. In patients who have a prolactinoma, there is an abnormally high level of prolactin secreted. This can lead to infertility, loss of normal menstruation, breast enlargement and secretion of a milk-like secretion from the nipples in women. This clinical syndrome is sometimes referred to as amenorrhea-galactorrhea. In men it can lead to impotence, enlargement of the breasts (gynecomastia), and secretion of a milk-like secretion from the nipples.
What Types of Symptoms Are Typical?
In women, high levels of prolactin can cause infertility, loss of normal menstruation, breast enlargement and secretion of a milk-like secretion from the nipples in women. This clinical syndrome is sometimes referred to as amenorrhea-galactorrhea.In men it can lead to impotence, enlargement of the breasts (gynecomastia), and secretion of a milk-like secretion from the nipples.
In addition to this clinical syndrome associated with secretion of prolactin, these pituitary adenomas can cause other symptoms typical of a pituitary adenomaincluding headache, visual changes and hypopituitarism.
How Is The Diagnosis Typically Made?
In addition to the standard imaging and blood tests done for all pituitary adenomas, a prolactinoma will be confirmed by very high blood levels of prolactin.What Are Some Common Treatments?
Prolactinoma is a unique pituitary adenoma in that there exist drugs which can help control the tumor in some patients. These medications, called dopamine agonists (bromocriptine and cabergoline), actually inhibit the tumor cells and decrease their secretion of prolactin and can even lead to decreased size of the tumor. While this effect can be profound in some patients, it may not be as effective in others.In very large tumors or in tumors which are not adequately controlled by dopamine agonist medications, surgery will sometimes also be recommended. As with other pituitary adenomas, these are generally approached through a transsphenoidal surgery through the nasal passage.
Each tumor and patient is different, so it is hard and inappropriate to make generalizations about what treatment plan is most appropriate. Each patient should discuss their options with their own physician team.
Pituitary Cyst: Rathke's Cleft Cyst
What Is It?
A Rathke's cleft cyst is a benign pituitary cyst which typically occurs in the area of the pituitary gland. It is thought to be a remnant of an embryologic structure called Rathke's pouch, hence the name. If left over after development, the cyst can slowly expand and eventually cause symptoms.Most Rathke's cleft cysts occur in the sella, the area where the pituitary gland sits, although occasionally they can occur in the suprasellar area, above the gland. They are typically consisted of a thin wall with a thick or gelatinous fluid inside.
These pituitary cysts can present anywhere from childhood through to late adulthood, although it is most frequently found in older adults.
What Types of Symptoms Are Typical?
Many Rathke's cleft cysts do not produce any symptoms and can be incidental findings. This is more true of smaller cysts.As they enlarge, they can compress the normal pituitary gland, the pituitary stalk and the optic chiasm above which is important for normal vision. Therefore, symptomatic cysts can cause various symptoms, most commonly including visual disturbances and pituitary hormonal disturbances.
These symptoms and when they present vary from patient to patient and depend much on the exact position of the pituitary cyst and its size.
How Is The Diagnosis Typically Made?
In the case of asymptomatic cysts, they may be found incidentally on CT scan or MRI scan or at autopsy.In the case of symptomatic cysts, after a neurological examination, they are often found on a CT or MRI scan. They appear as a cystic structure in the area of the pituitary gland. While the diagnosis can be fairly confident based on these imaging studies, not all cysts can be distinguished from other pathologies that occur in the region such as a pituitary adenoma or a craniopharyngioma.
A definitive diagnosis is made at the time of surgery when the cyst with fluid contents is confirmed and sent to pathology for inspection.
In addition, because they can effect normal pituitary function, most patients will undergo a thorough endocrinological work-up with blood tests of several pituitary and related hormones.
What Are Some Common Treatments?
Asymptomatic cysts are often treated conservatively, watching them on serial scans and waiting until a patient has symptoms.If the decision is made by the patient and their physicians, these pituitary cysts are generally treated surgically. Most can be treated by a transsphenoidal surgery, through the nasal passages. In most cases the cyst can be drained and at least some of its capsule removed. If the cyst wall is strongly adherent to important structures such as the pituitary stalk, small remnants are sometimes left intact.
As with other tumors, the specific treatment plan varies from patient to patient and cannot be generalized. Patients should make these treatment decisions with their own personal physician.
Schwannoma
What Is It?
A schwannoma is a benign tumor of Schwann cells, the cells that insulate nerve cells in the peripheral nervous system. They occur on peripheral nerves, not in the brain or spinal cord itself. Normally, Schwann cells aid in the conduction of normal electrical impulses along nerve fibers. This tumor is the result of abnormal growth of these cells.Schwannomas can occur anywhere along peripheral nerve fibers. They create a bulge on the nerve and can slowly grow. In the intracranial compartment (in the head), the most common location for these tumors is on the vestibulocochlear nerve (also called cranial nerve VIII). This nerve brings sensory information back to the brain from the inner ear. It has both cochlear fibers which carry hearing information and vestibular fibers which carry information about balance. These tumors almost always occur on the vestibular portion of the nerve. This specific type of schwannoma is referred to either as an Acoustic Neuroma or a Vestibular Schwannoma
While most of these tumors occur sporadically without a known cause, some familial genetic disorders can give rise to frequent growth of this type of tumor, most notably neurofibromatosis. The great majority of these tumors are benign, but rarely malignant types have been described.
What Types of Symptoms Are Typical?
Symptoms vary considerably depending on which nerve is affected. Generally, the normal function of the nerve will be compromised. So in a peripheral nerve that serves motor and sensory function, it would not be uncommon to have numbness or tingling as well as muscle weakness in the distribution of that nerve. Pain is also possible.In the case of an acoustic neuroma (vestibular schwannoma), the typical first symptoms include tinnitus (ringing in the ear) and hearing loss in one ear, due to damage to the adjacent cochlear nerve. While there are many causes of hearing loss in both ears, there are only a handful of causes that can cause monaural hearing loss. In addition, as the tumor gets larger, other symptoms can occur including facial weakness, headache and others.
How Is The Diagnosis Typically Made?
The diagnosis of schwannoma varies depending on its location. Typically, symptoms or a mass will lead to a neurological evaluation and some sort of imaging study to identify the mass. In the case of intracranial tumors, such as an acoustic neuroma, a head CT scan or MRI scan is usually performed.Definitive diagnosis usually requires a tissue sample so that a pathologist can analyze the tumor and differentiate it from other tumors that can occur on nerves.
What Are Some Common Treatments?
Again, treatments vary considerably depending on the location. Small, asymptomatic tumors will sometimes just be watched until they enlarge or begin causing symptoms. However, most tumors will eventually require surgical treatment. Because the great majority of these tumors are benign, the goal of surgery is to remove it in its entirety, which gives the best chance of a complete cure. The surgical approach varies depending on the location of the tumor. The specific treatment plan of each patient should be discussed with that patient's treating physician(s).In the case of acoustic neuroma, there are various approaches to this complex area, some of which aim at preserving hearing and some of which loose the hearing in that ear completely. One of the most common complications of these procedures is damage to the facial nerve, which runs right alongside the vestibular nerve. If it is damaged at the time of operation, it can lead to temporary or permanent facial muscle weakness in some cases.
Acoustic Neuroma (Vestibular Schwannoma)
What Is It?
An acoustic neuroma is a specific type of tumor that occurs adjacent to the brain stem. Although the term acoustic neuroma is still frequently used, the more appropriate name for the tumor is a vestibular schwannoma. It is typically a benign tumor which arises from Schwann cells on the cranial nerve bringing balance information from inner ear back to the brain stem, the vestibular component of the vestibulocochlear nerve (8th cranial nerve). Although schwannomas in general can occur on virtually any peripheral nerve, this vestibular nerve tumor is one of the most common forms.Although this type of tumor is technically a peripheral nerve tumor, it is often referred to as a brain tumor because of its close approximation to the base of the brain. Vestibular schwannomas are also sometimes referred to as a skull base tumor because they occur at the base of the skull, adjacent to the temporal bone and the inner ear.
These tumors typically begin growing in the internal auditory canal, the opening in the bone through which the nerves travel from the inner ear to the brain stem. As they enlarge they can grow out of the canal into the space adjacent to the brain stem and can eventually put pressure on the brain stem itself when large enough.
Although acoustic neuroma is relatively uncommon in the general population, there is a genetic disorder which greatly increases the risk for this tumor as well as others. Neurofibromatosis type 2 (NF 2) is a genetic disorder caused by a mutation of a specific gene. Individuals with the mutated gene have a tendency to develop schwannomas as well as some other types of tumors. In these patients, bilateral vestibular schwannomas (occuring on both sides) is not uncommon.
What Types of Symptoms Are Typical?
As an acoustic neuroma grows on the vestibular nerve it causes damage to the nerve and can cause vertigo and/or dizziness. Additionally, because of pressure on the adjacent cochlear nerve, which brings hearing sensation to the brain from the inner ear, most patients experience unilateral hearing loss and/or tinnitus (ringing) in that ear. The hearing loss and tinnitus only involve one ear. The hearing loss is gradual and usually involves higher frequencies first. Patients often complain that they first notice a problem understanding voices when trying to talk on the phone with that ear. Unilateral hearing loss, dizziness and tinnitus are the most common presenting symptoms.As the tumor enlarges it can cause additional symptoms. Headache is not uncommon. Compression of the adjacent facial nerve can cause weakness on that side of the face. As the tumor gets very large it can compress the brain stem and cause many other symptoms and can even cause obstructive hydrocephalus which can be life-threatening. However, these tumors tend to be rather slow growing so the progression of these symptoms generally occur over months to years.
How Is The Diagnosis Typically Made?
Unilateral hearing loss, tinnitus and/or dizziness are usually worked up with a thorough ear examination and testing called audiometry. The audiogram evaluates the hearing and can demonstrate the severity and type of hearing loss. These patients will also typically undergo an imaging study, most frequently an MRI, to identify the tumor. The typical location and appearance of this tumor make its diagnosis on MRI typically straightforward. However, to positively identify the tumor as a schwannoma and rule out other types of tumors a piece of the tumor (a biopsy) is needed to be evaluated by a pathologist.What Are Some Common Treatments?
The earlier these tumors are diagnosed and treated, the better the outcome, typically. While some patients and their physicians may choose to simply wait and observe the tumor with serial MRIs if the tumor is very small and causing minimal symptoms, most patients will decide to undergo some type of treatment of the tumor. Traditionally, the treatment offered is a surgery to remove the tumor. There are various types of surgical procedures which can be performed depending on the tumor size, symptoms and surgeon preference. The goal is generally to remove as much of the tumor as possible. If the complete tumor is removed, the risk of recurrence for these benign masses is generally very low.Because of the close proximity of these tumors to the facial nerve, which supplies the muscles of the face, injury to the facial nerve is one of the most important complications which can occur with these procedures. While in most cases the nerve can be identified and protected, in a small number of cases the nerve is injured and can result in a transient or permanent facial weakness (palsy) on that side of the face.
Another option for treatment of some acoustic neuromas is radiosurgery with focused-beam radiation. The goal is to irradiate the tumor with high energy radiation to kill the dividing cells. This treatment avoids a surgery but generally does not result in the tumor disappearing completely. However, it often slows or halts the growth of the tumor and in some cases the tumor will shrink after treatment. This is sometimes considered as a primary treatment of the tumor, particularly for small tumors. However, it is also considered for treating recurrent or residual tumors after prior surgical treatment. If an acoustic neuroma is treated with radiation or there is a residual left behind after surgery, these patients generally require long-term follow-up with occasional MRI scans to track the progression of the tumor.
The ideal management and treatment of these tumors vary depending on the specifics of each case. Each patient should discuss their options with their own treating physicians.
Teratoma
What Is It?
A teratoma is a type of tumor which is derived from abnormal development of embryologic cell types. In other words, cells during development continue growing in a location that they should not remain. They are considered to be congenital (present at birth) and they fall into a class called germ cell tumors.Like other related tumors, such as Dermoid cyst, they have remnants of other tissues growing in a place they should not. They, unlike a Dermoid cyst, can have all three layers of germ cells present, giving rise to various tissues in the tumor which resemble other organs or tissues. For example, a teratoma can have skin, hair, teeth, sweat glands, lung tissue, brain tissue and other various types of tissue. While they do not generally create whole organs, any one teratoma can have several tissues in it that resemble various tissue types from elsewhere in the body.
Teratomas (literally Greek for "monstrous tumor") can occur in several places in the body. While teratomas of the ovaries is more common, they can occur in the central nervous system as well.
The great majority of these tumors are benign and called "mature". However, rarely, immature, or benign variants can occur.
What Types of Symptoms Are Typical?
The symptoms associated with these tumors vary depend on its size and location. As they enlarge they can compress neurological structures, leading to neurological symptoms. These symptoms are entirely dependent on the location, but can include numbness or weakness in a part of the body, hearing or visual difficulties, as well as other nervous system deficits.How Is The Diagnosis Typically Made?
After an in depth neurological examination, typically a CT scan or MRI scanof the brain or spine will reveal the cystic mass. While the appearance of these tumors is fairly characteristic, it can be confused for some other types of tumors. It should be distinguished from an epidermoid cyst, which is a similar cyst but which only contains epithelial tissue, and a dermoid cyst, which is similar to an epidermoid except that it can have dermal appendages such as hair and hair follicles, sweat glands, teeth, etc.As with other tumors, to make a definitive diagnosis, tumor tissue is required to be analyzed by a pathologist.
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