Types of Benign Brain Tumor

Different types of benign brain tumors develop in various parts of the brain. Although they are non-cancerous, they can be harmful in the long run if left untreated.

A brain CT scan showing a cross-section of the brain with a benign brain tumor

Benign brain tumors are often misinterpreted at the early onset. This is because there are different types of benign brain tumors with most of them presenting with common symptoms like headache, fever, and tingling of the ear.

These shared symptoms are typical symptoms of other health conditions such as ear infections or malaise - this usually makes those affected misinterpret brain tumors as other health conditions.

The implication is that most times when the actual symptoms start presenting, it becomes dangerous and a bit late to tackle. If not detected early, brain tumors can grow bigger, increasing the pressure inside the skull, and this can be life-threatening.

In a previous article, SemicHealth covered the different types of benign tumors, their causes, and where they are often located. In this article, we will cover the different types of benign brain tumors, their causes, symptoms of benign brain tumors, as well as treatment.

What are benign brain tumors?

Benign brain tumors are non-cancerous tumors found in the brain. Like most benign tumors, benign brain tumors grow slowly, making them undetected for a long time. This is one major feature that differentiates benign tumors from malignant tumors.

Benign brain tumors do not spread in the brain; they often stay localized. Most times, when the tumors are completely removed during surgery, they don't recur. But when the tumors are not completely removed, they could come back.

However, the skull is enclosed, so any tumor that grows within it, whether benign or malignant, has a great chance of pressing on some sensitive brain tissues, causing harmful side effects.

Causes of Benign Brain Tumors

Like other types of benign tumors, the causes of benign brain tumors are mostly unknown. There are no definite causes associated with them. However, there are a few pointers on the possible causes or risk factors for benign brain tumors, such as:

  • People over 50 have a high chance of having a benign brain tumor.
  • If you have a family history of brain tumors, there are chances you might develop it.
  • You might develop a brain tumor if you have genetic conditions like neurofibromatosis type 1, tuberous sclerosis, neurofibromatosis type 2, and Li-Fraumeni cancer syndrome. These genetic conditions can increase your risk of developing a non-cancerous brain tumor.

Types of Benign Brain Tumors

There are different types of benign brain tumors, each occuring in different parts of the brain Photo by MART PRODUCTION on Pexels

There are various types of benign brain tumors, each with different characteristics and locations. Types of benign brain tumors include:

1. Meningioma

Meningioma is the most common type of benign brain tumor, accounting for about 53.3% of the non-malignant tumor and 37.6% of all tumors. Meningioma is a non-cancerous central nervous system tumor.

It begins from the meninges of the brain and spinal cord (meninges are layers of tissue that cover and protect your brain and spinal cord).

Some factors that can lead to meningiomas include hormonal therapy, family history, exposure to radiation, and neurofibromatosis.

Meningiomas are more commonly found in men than women due to hormonal factors.

Meningiomas are of three types: Grade 1 or typical, grade 2 or atypical, and grade 3 or anaplastic. Grade one grows slowly, is non-cancerous, and accounts for most cases of this brain tumor type. Grade 2 grows faster than grade 1 and is also non-cancerous. Grade 3 is cancerous and grows faster than grades 1 and 2.

Since grade 1 meningioma grows slowly, you might not notice the symptoms till a later stage. Still, the more common symptoms include headaches, hearing loss, seizures, dizziness, nausea, vomiting, etc.

Meningiomas can be treated using surgery, especially when it has fast growth. It can also be treated using radiotherapy. For patients who cannot undergo surgery due to underlying causes, stereotactic radiosurgery can be used. The stereotactic method is mainly used when the meningioma is reoccurring.

About 1 to 3% of this benign tumor type can turn into malignant tumors if not correctly managed. Also, its survival rate is usually low.

2. Craniopharyngioma

Craniopharyngioma is a type of benign brain tumor. It is one of the benign tumors that rarely occurs. It has slow growth, and it usually arises close to the brain's pituitary gland (the pituitary gland functions to secrete hormones that control various body functions).

Craniopharyngioma usually affects the functions of the brain's pituitary gland because it grows near it. It can also lead to the compression of the optic chiasm.

Craniopharyngioma is more prevalent between the ages of 5 to 14 and 50 to 74. Craniopharyngiomas usually have a high reoccurrence rate.

It is often accompanied by symptoms like nausea and vomiting, headaches, hormonal disturbances, and visual and endocrine disturbances.

It is always challenging to treat craniopharyngioma because of its closeness to neurovascular structures, location, and invasiveness. However, if you are diagnosed with this condition, your oncologist will know the best line of treatment to use. The treatment options may include radiotherapy and surgery.

3. Nasopharyngeal Angiofibroma

This type of benign brain tumor is rare. It is a highly vascular tumor in the posterior nasal cavity(at the back of the nose).

Although this is a benign brain tumor, it is considered severe because it can spread from the posterior nasal cavity to the eye socket, sinuses, skull, and brain.

Nasopharyngeal Angiofibroma is also called juvenile nasopharyngeal angiofibroma (JNA). This is because it usually affects adolescent or prepubescent males between the ages of 10-20. This tumor has only occurred in females on rare occasions.

The most common symptoms of JNA include headache, rhinorrhea (running nose), sleep apnea, bulging eyes, watery eyes, etc. In more severe cases, the symptoms can be a visual disturbance, cranial nerve palsy, and proptosis.

The most common treatment for JNA is surgery. In cases where the tumor keeps reoccurring, radiotherapy may be used.

4. Choroid plexus papilloma

This is a type of benign brain tumor that affects the choroid plexus. They are primarily seen in infants. The choroid plexus tumor in infants usually leads to a change in the mental status and sometimes increasing head circumference.

When it occurs in adults, it presents with signs of intracranial tension like headache, vomiting, visual field defects, and lateral gaze palsies.

5. Pituitary Adenoma

Pituitary adenomas are benign tumors of the pituitary gland.

This type of benign brain tumor presents with symptoms such as headache, visual problems, excessive weight gain, irregular menstrual flow, erectile dysfunction, and issues in lactation.

Pituitary adenomas are classified based on their size and hormone-secreting activities.

The hormone-secreting pituitary tumors are called active endocrine tumors, whereas those that don't secrete hormones are considered inactive.

6. Hemangioblastoma

This is another type of benign brain tumor. It is a vascular tumor that forms in the lower part of the brain, spinal cord, and retina.

Although it starts as benign, this tumor is considered a sensitive one. The tumor, while enlarging, usually adds pressure on the brain. This leads to some neurological symptoms like weakness, headache, sensory loss, and loss of balance and coordination. It also leads to a build-up of spinal fluid in the brain (hydrocephalus).

The exact cause of hemangioblastoma is unknown, but it has been broadly associated with an inherited condition called von Hippel-Lindau (VHL).

Hemangioblastomas typically cause symptoms such as headache, nausea, vomiting, and loss of coordination and balance.

7. Lipomas

Lipomas are non-cancerous tumors made up of fatty tissues. Their appearance usually signifies the presence of other congenital anomalies.

Lipomas are of different sizes, and they can be single or multiple. They can go undetected for a long time because they barely present any symptoms. However, they are often always detected when a scan is performed.

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Other benign brain cysts and lesions

Brain cysts are fluid-filled sacs in the brain. Similar to brain tumors, brain cysts can be cancerous or non-cancerous. Brain cysts are usually filled with pus, blood, or other materials.

Brain cysts are caused as a result of a build-up of fluid in the brain. They usually appear during the first week of intra-uterine life (in the womb). Sometimes, the cysts also form due to trauma or an injury to the head.

Some types of brain cysts include:

1. Colloid Cyst

Colloid cysts are a type of brain cyst found in the third ventricle. The cyst comprises an epithelial lining filled with gelatinous material and contains old blood, cholesterol, mucin, and ions.

Colloid cysts rarely cause sudden death, but they usually present with symptoms like headache, diplopia, and memory problems.

If a colloid cyst causes hydrocephalus (build of fluid in the ventricle), it will need to be treated to avoid damage. The hydrocephalus will also need to be treated first before the cyst.

The treatment of colloid cyst is usually through a craniotomy(a surgery where an incision is made on the scalp). There are other methods too. Your healthcare team will best determine the appropriate treatment method.

2. Encephalocele

Encephalocele is a congenital disability caused by incomplete closure of the neural tube. The brain and the spinal cord forms within the neural tube, and when it fails to close completely, Encephalocele occurs. This usually happens between the third and fourth weeks of pregnancy and can appear in the skull's base, top, or back.

Encephalocele mainly arises due to genetic effects. It is common in families with other histories of neural tube defects like spina bifida.

Encephaloceles usually lead to facial and cranial deformities. These deformities can be corrected using surgery.

3. Dermoid and Epidermoid Cyst

Dermoid and Epidermoid cysts are benign growths that mainly affect the spine. They are harmless, but as they grow, they compress nearby structures, leading to some symptoms.

Some of the symptoms associated with dermoid and epidermoid cysts include weakness, incontinence, problems with balance, etc.

The significant difference between dermoid and epidermoid cysts is in their content. Epidermoid cysts contain protein keratin and other products of skin cells and also accumulated skin cells. On the other hand, dermoid cysts contain other skin components like hair or sweat glands, skin cells, and other materials like blood.

4. Arachnoid Cyst

Arachnoid cysts can press on important structures in the brain causing symptoms like headache. Photo source: Kindel Media on Pexels

Arachnoid cysts are benign cysts found on the brain and spinal cord. They can only have a negative effect when they press against other structures.

They usually occur at birth or after a trauma to the head(which affects children more).

If an arachnoid cyst presses on other structures, it could cause symptoms like dizziness, nausea, vomiting, seizure, or headaches. The symptoms vary from one individual to another

5. Rathke's Cleft Cyst

Rathke's cysts are non-cancerous cysts that form at the base of the brain in some parts of the pituitary gland. They are congenital because they start when the fetus is in the womb.

Rathke's cysts occur due to the persistence of Rathke's pouch. When the Rathke's pouch persists, it gives room for a cyst to form.

Rathke's cysts develop when the child is in the womb, but it is undetected till a later stage in adulthood.

When Rathke's Cyst starts to press on other structures later, it leads to symptoms such as reoccurring headaches, nausea, personality or mood changes, vision changes, etc.

Symptoms of Benign Brain Tumors

Benign brain tumors present varying symptoms depending on the size, location, and type of tumor.

The common symptoms include

  • Seizures
  • Headaches
  • Facial tingling or numbness
  • Nausea or vomiting
  • Visual problems

Diagnosis for Benign brain tumors

Benign brain tumors may be difficult to detect at an early stage because they often present with mild symptoms that start slowly. Their diagnosis may be a bit challenging - in fact, most benign brain tumors are usually diagnosed in the course of other treatments.

Your doctor can order tests like CT scan and brain MRI if they suspect a brain tumor Photo by MART PRODUCTION on Pexels

The primary diagnosis is always a physical examination. During this examination, your healthcare provider will ask questions like:

  • The symptoms you are having
  • Your medical history
  • Medication record
  • Previous surgeries and medical treatments
  • Family medical history

You could also be asked to go in for a physical examination where you will be screened for:

  • Mental status
  • Vision
  • Balance and coordination
  • Reflexes

You could also be asked to run tests like CT Scan, Brain MRI, and Spinal Tap to help your doctor see the structures within your brain and possibly detect any abnormality.

Treatment for Benign Brain Tumors

The treatment options for brain tumors depend on the type and severity:

  • Surgery is the most common treatment option. Here, the aim is always to remove as many tumors as possible.
  • Radiotherapy - This is often used in the case of reoccurring tumors.
  • Chemotherapy - This is also used to kill off the remaining cells after surgery.
  • Radiosurgery - This is applied when the tumors are hard to locate and remove.

Your healthcare provider is always in the best position to determine the treatment most suitable for you.

When to see a doctor

Benign brain tumors are barely visible to the eyes. Unless in cases where they cause swellings in the head (which often doesn't happen immediately after the tumor growth starts), they may go undetected for a long time.

However, you should visit your health care provider when you start noticing symptoms like persistent headaches, vision problems, balance and coordination problems, and ear tingling.

Also, you should see your doctor if you have any form of head injury or trauma.

Conclusion

The brain is a susceptible part of the body. Unfortunately, it is not immune to tumors as different types of tumors can develop there. Any tumor in the brain, whether benign or malignant, should be treated as urgent.

A regular scan is advised for everyone because most benign brain tumors go undetected for a long time. Early detection makes for early treatment which often increases the chances of survival and recovery.

References

  1. Joseph JJ, M Das J. (2022). Choroid plexus Papilloma
  2. Josesph W, Margaret W, Elizabeth B. (2010). Epidemiology and etiology of meningioma.
  3. Ortiz T, Shafiq I, Mesfin FB. (2022). Craniopharyngioma
  4. Patrick O, Abel P, Spencer C et al. (2018). Nasopharyngeal angiofibroma in a 32-year-old man
  5. Quinn T et al. (2019). CBTRUS Statistical Report: Primary Brain and Other Central Nervous System Tumors Diagnosed in the United States in 2012-2016
  6. Tenny S, Thorell W. (2022). Colloid Brain Cyst
  7. Yu Seok Lim et al.(2013). Long Term Clinical Outcomes of Malignant Meningiomas