What are the other Names for this Condition? (Also known as/Symptoms)

• Central Nervous System Endodermal Cyst
• Enterogenous Cyst of Central Nervous System
• Neurenteric Cyst (NC)

What is Endodermal Cyst of the Central Nervous System? (Definition/Background Information)

• Endodermal Cysts of the Central Nervous System are highly uncommon and benign lesions with a congenital origin. These endodermal cysts are also known as Neurenteric Cysts (NCs) or Enterogenic Cysts and are observed in a wide age range of individuals
• The brain along-with the spinal cord constitute the central nervous system (CNS) of the body. A large majority of the endodermal cysts are observed in the spinal cord (Intraspinal Endodermal Cysts); some are seen in the brain (Intracranial Endodermal Cysts)
• The cause of formation of an Endodermal Cyst of the Central Nervous System is unknown. Also, presently, the risk factors for the same are not well-established. These lesions are believed to develop during pregnancy due to abnormal embryogenesis of endodermal cells
• Small-sized Endodermal Cysts of the Central Nervous System may not present any significant signs and symptoms. However, large cystic tumors may cause headaches, memory issues, back pain, numbness, weakness of the lower extremities, or loss of bladder/bowel control, depending on the location of the tumor in the CNS
• In some cases, the treatment of Central Nervous System Endodermal Cyst may involve surgery. In most cases, the prognosis is excellent with appropriate early treatment, since it is a benign cystic lesion. However, an incomplete removal may result in tumor recurrences, and occasionally such recurrent tumors may undergo malignant transformations

Who gets Endodermal Cyst of the Central Nervous System? (Age and Sex Distribution)

• Endodermal Cysts of the Central Nervous System are extremely uncommon tumors that are seen across all age groups
• Both males and females are affected
• No specific racial or ethnic group predilection is noted

What are the Risk Factors for Endodermal Cyst of the Central Nervous System? (Predisposing Factors)

• Currently, no definite risk factors have been identified for Endodermal Cyst of the Central Nervous System

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Endodermal Cyst of the Central Nervous System? (Etiology)

The cause of development of Endodermal Cyst of the Central Nervous System is generally unknown.

• These cysts arise from the endoderm, which is the innermost germ layer seen during the development of an embryo. During embryological development, a neurenteric canal (axial canal) forms, which is a temporary connection between the yolk sac and amnion
• This connection is necessary for normal development of a fetus. As the fetus develops and pregnancy progresses, this temporary connection is no longer needed and hence it disappears
• Persistent presence of this temporary connection results in the development of an endodermal cyst. In other words, the CNS Endodermal Cyst is believed to occur from incomplete resorption of this neurenteric canal

The condition is not caused by what the expectant mother does or does not do, either prior to or during pregnancy.

What are the Signs and Symptoms of Endodermal Cyst of the Central Nervous System?

The signs and symptoms of Endodermal Cysts of the Central Nervous System can vary from one individual to another and depends on the size and location of the cystic tumor. Typically, a majority are less than 1 cm in size and present no significant symptoms.

In general, most cysts are small, and no significant symptoms are observed; although, large tumors are known to present symptoms. In many individuals, tumors that grow slowly and remain asymptomatic, may be diagnosed during certain radiological imaging studies of the head and neck or spinal cord region, which are performed for unrelated health conditions.

Most of these fluid-filled lesions are observed in the spinal cord (75% of the cases), and some are observed in the brain. The intraspinal lesions may be intramedullary (arising from inside the spinal canal) or extramedullary (from outside the spinal canal). Many are noted in the upper back (cervicothoracic junction) or lower end of the spine (conus medullaris). Intracranial lesions or Intraparenchymal Endodermal Cysts are usually observed in the posterior fossa; tumors at supratentorial sites are very rare.

The signs and symptoms of Endodermal Cyst of the Central Nervous System may rarely include:

In the brain:

• Headaches
• Vision impairment, if the optic nerve is affected
• Hearing impairment
• Numbness and tingling sensation
• Muscle weakness; ataxia
• Movement/walking difficulties
• Memory disturbances

In the spinal cord:

• Presence of visible lump in the affected region
• Back pain and/or chest pain
• Numbness and tingling sensation
• Weakness of the body or lower extremities; loss of strength in the arms of legs
• Pain in the arms and legs, depending on the nerves that are compressed by the tumor
• Spinal cord compression leading to numbness and pain, due to mass effect of the tumor
• Severe cases may result in loss of bowel and bladder control
• Paralysis

How is Endodermal Cyst of the Central Nervous System Diagnosed?

There are a variety of tests the healthcare provider may employ to diagnose Endodermal Cyst of the Central Nervous System, which may include:

• Physical examination and complete medical history screening
• Assessment of the presenting signs and symptoms
• Neurological, motor skills, and cognitive assessment:
  • Checking intellectual ability, memory, mental health and function, language skills, judgment and reasoning, coordination and balance, reflexes, and sensory perceptions (space, sight, hearing, touch, etc.)
  • The healthcare provider/neurologist may use the Karnofsky Performance Scale in order to assess the neurological functioning of the individual’s central nervous system (CNS)
• Electroencephalography (EEG)
• Electromyography with nerve conductivity tests
• Imaging studies that may be performed include:
  • X-ray of head and neck region or vertebral column
  • Computerized tomography (CT) scan of the head and neck region/vertebral column; CT with contrast
  • Magnetic resonance imaging (MRI) scan of the central nervous system (brain and spine); MRI with contrast agents such as gadolinium
  • Cerebral angiographic studies or MR angiography: An angiogram involves injecting dye into the bloodstream, which makes the blood vessels to appear visually on X-rays. The X-ray may show a tumor in the brain or the blood vessels leading into the tumor
  • Magnetic resonance spectroscopy: This radiological technique is used to study the chemical profile of the tumor. It is often performed with and compared to corresponding MRI scan images of the affected region
• Cerebrospinal fluid analysis, where a spinal tap or lumbar puncture procedure may be performed: This diagnostic test is used to remove a sample of cerebrospinal fluid (CSF) from the spaces in and around the brain and spinal cord. The sample is removed from the lower spinal cord using a thin needle, and it is then checked for the presence of cancer cells
• Molecular studies, if necessary

Tissue biopsy: A biopsy of the affected region (brain or spinal cord) is performed and sent to a laboratory for a pathological examination. A pathologist examines the biopsy sample under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis. Examination of the biopsy sample under a microscope by a pathologist is considered to be gold standard in arriving at a conclusive diagnosis.

A differential diagnosis to eliminate other conditions or tumor types may be considered, before arriving at a definitive diagnosis.

The radiological differential diagnosis may include:

• Arachnoid cyst
• Chordoma
• Cystic schwannoma
• Ecchordosis physaliphora
• Epidermoid cyst of CNS
• Intracranial lipoma

The pathological differential diagnosis may include:

• Choroid plexus cyst
• Colloid cyst
• Cystic tumors of CNS
• Glioependymal cyst
• Papillary endolymphatic sac tumor

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Endodermal Cyst of the Central Nervous System?

The complications of Endodermal Cyst of the Central Nervous System may include the following:

• Stress and anxiety due to fear of an intracranial or intraspinal tumor
• Severe memory deterioration from tumors in the brain
• Large tumor masses may get secondarily infected with bacteria or fungus
• Occasionally, spontaneous hemorrhaging (bleeding) of the cystic lesion has been observed
• Tumor rupture may cause a form of meningitis, called chemical meningitis
• Occasionally, recurrence of the tumor following its incomplete surgical removal has been noted; such a recurrence may occur from a few months to even several decades after the surgery
• Recurrent tumors may be noted in the brain regions, in the vicinity of the original cysts 
• Longstanding cysts and recurrent cysts may transform into malignancy (over a long period) in rare occasions. In such cases, they may even migrate to other regions
• Damage to the muscles, vital nerves, and blood vessels, during surgery
• Post-surgical infection at the wound site

How is Endodermal Cyst of the Central Nervous System Treated?

The treatment of Endodermal Cyst of the Central Nervous System may involve the following:

• In some cases of small-sized tumors and considering their slow-growing rates, the healthcare provider may propose conservative ‘wait and watch’ measures, instead of immediately recommending surgery to remove them
• Generally, the treatment of choice is a complete surgical excision for all such lesions. The surgeon may perform a craniotomy or employ other microsurgical approaches to remove the cyst
• Additionally, chemotherapy and/or radiation therapy may be necessary for malignant tumors
• Follow-up care with regular screening and check-ups are important and encouraged

How can Endodermal Cyst of the Central Nervous System be Prevented?

Currently, there are no known methods to prevent the development of Endodermal Cyst of the Central Nervous System.

What is the Prognosis of Endodermal Cyst of the Central Nervous System? (Outcome/Resolutions)

• The prognosis of Endodermal Cyst of the Central Nervous System is usually excellent with complete surgical removal of the tumor, since it is a benign tumor
• In case of a malignant transformation of the benign cystic tumor, the prognosis depends on several factors including on the stage of the tumor

Additional and Relevant Useful Information for Endodermal Cyst of the Central Nervous System:

The following article link will help you understand other cancers and benign tumors:

http://www.dovemed.com/diseases-conditions/cancer/