
Intracranial epidermoid cysts develop in the early embryonic phases. The cysts develop when epithelial cells are confined with cells that form the brain.
Signs and symptoms
Review of past cases, patients often do not exhibit many symptoms or obtain a diagnosis until they are around 20 to 40 years old. If the patient does show symptoms, it is most likely due to pressure from growth of the tumor. Depending on which part the epidermoid is pressing against can result in varying symptoms.
*
Headaches
Headache is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches.
Headaches can occur as a resul ...
– often worse in the morning or by changing positions; can be constant and become more severe or more frequent; not your typical headache
*
Vision problems
Visual impairment, also known as vision impairment, is a medical definition primarily measured based on an individual's better eye visual acuity; in the absence of treatment such as correctable eyewear, assistive devices, and medical treatment� ...
like blurred vision, double vision, or loss of peripheral vision
* Loss of sensation or movement in the arms, legs, or face
*
Dizziness
Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to disequilibrium or a non-specific feeling, such as giddiness or foolishness.
Dizziness is a common medical ...
or difficulty with balance and walking, unsteadiness, vertigo
* Speech difficulties
* Confusion in everyday matters or disorientation
* Seizures, especially in someone who hasn’t had seizures before
* Hearing loss or buzzing or ringing in the ear
* Swallowing or speech difficulty
* Fatigue or sleepiness especially in children
Cause
These tumors arise when
epidermal
The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water rele ...
cells become trapped during
neural tube
In the developing chordate (including vertebrates), the neural tube is the embryonic precursor to the central nervous system, which is made up of the brain and spinal cord. The neural groove gradually deepens as the neural fold become elevated, ...
closure. This occurs between the 3rd to 5th week of
fetal development
Prenatal development () includes the development of the embryo and of the fetus during a viviparous animal's gestation. Prenatal development starts with fertilization, in the germinal stage of embryonic development, and continues in fetal devel ...
.
Pathophysiology
The chances of intracranial epidermoids is about 1% of all brain tumors. This benign tumor of the brain is made up of normal skin cells (stratified epithelial lining) on the outside, and fatty acids and keratin are on the inside of the tumor or sac. Only the sticky outer membrane is alive thus sticking to brain tissues and nerves.
Epidermoid tumors strongly adhere to the
brain stem
The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is cont ...
or
cranial nerves
Cranial nerves are the nerves that emerge directly from the brain (including the brainstem), of which there are conventionally considered twelve pairs. Cranial nerves relay information between the brain and parts of the body, primarily to and ...
. Often the lining of the tumor connected to the brain stem or parts difficult to "peel" away are left behind leaving residual tumor after surgery, this can contribute to the risk of regrowth.
About 40% of these cysts originate in the
cerebellopontine angle
The cerebellopontine angle (CPA) ( la, angulus cerebellopontinus) is located between the cerebellum and the pons.
The cerebellopontine angle is the site of the cerebellopontine angle cistern one of the subarachnoid cisterns that contains cerebro ...
.
Diagnosis
Magnetic resonance imaging (MRI) and
computed tomography
A computed tomography scan (CT scan; formerly called computed axial tomography scan or CAT scan) is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers ...
(CT) brain scans can be used to identify these tumors.
Treatment
Treatment to remove these tumors always involve radical surgery. The reported recurrence rate for a subtotal removal is 30% after a mean interval period of 8.1 years.
Surgery is the primary treatment for removal of the brain tumor. Use of an endoscope may assist on obtaining a more complete surgical removal from hidden recesses.
It has been seen that a few patients have tumors that grow unusually fast, especially after surgery. After surgery it is highly suggested the patients get quarterly MRI's to monitor their tumors or as per neurosurgeons/neurologists order. If monitoring the tumor, it is suggested to use the same facility for each scan. Using different facilities can result in minor variations in the scan which can result in false measurements of the brain tumor.
Intracranial epidermoid tumors are slow growing lesions, which may recur after incomplete removal during surgery, although it will most likely take many years. These slow growing benign brain tumors envelop nerves and arteries rather than displacing them.
References
{{Reflist
Brain tumor
Cysts