Embryonal Tumors

The fetal (embryonic) cells in the brain are the origin of embryonic tumors of the central nervous system, which are cancerous (malignant) tumors. While embryonic tumors can develop at any age, they most frequently do so in infants and young children.

Some examples of embryonal tumors include −

• Medulloblastomas. These rapidly expanding malignant brain tumors, the most prevalent kind of embryonal tumor, begins in the cerebellum, a lower back region of the brain. Movement, balance, and muscular coordination are all regulated by the cerebellum. While they seldom expand to other parts of the body, medulloblastomas frequently disseminate through the cerebrospinal fluid (CSF) to other regions around the brain and spinal cord.

• Rosettes with several layers make up embryonic malignancies (ETMRs). ETMRs are uncommon malignant tumors that primarily affect newborns and young children. The biggest region of the brain, known as the cerebrum, which regulates thought and voluntary movement, is where these aggressive tumors most frequently begin. Other regions of the brain can also experience ETMRs, which are frequently defined by a specific genetic mutation.

• Medulloepitheliomas. These uncommon, rapidly growing malignant tumors usually affect newborn’s and young children's brains or spinal cords.

• Rhabdoid/teratoid cancers are unusual. The cerebellum of newborns and young children under the age of three is where these uncommon, malignant tumors are most frequently seen.

• Other malignancies of the embryo. The majority of malignant tumors that were originally known as primitive neuroectodermal tumors (PNETs), arising in the brain and spinal cord, fall within the category of embryonal tumors not otherwise described.

Embryonal Tumors: Causes

An embryonal tumor's origin is typically unknown. Nevertheless, several genetic conditions, such as Turcot syndrome, Rubinstein-Taybi syndrome, Nevoid basal cell carcinoma (Gorlin) syndrome, Li-Fraumeni syndrome, and Fanconi anemia, enhance the likelihood of acquiring this form of tumor.

Embryonal Tumors: Symptoms

The patient with embryonal tumors mainly presents with the following symptoms that include −

• Balance issues, difficulties walking, a loss of coordination, or slurred speech.

• Headache, particularly in the morning, or a headache that disappears after throwing up.

• General weakness or facial weakness on one side.

• Unusually low energy or drowsiness.

• Seizures

• Additional eye issues, such as double vision.

• Vomiting and nauseous

These tumors can cause irritability in young children and infants as well as sluggish growth. They could also have trouble eating or reaching developmental milestones like sitting, walking, and speaking whole phrases.

Embryonal Tumors: Risk Factors

Having any of the following hereditary conditions increases your risk of developing medulloblastoma and other CNS embryonal tumors −

• Turcot disease.

• syndrome of Rubinstein-Taybi.

• Nevoid Gorlin syndrome (basal cell carcinoma).

• Syndrome of Li-Fraumeni.

• Anemia Fanconi.

Genetic testing may be recommended for kids with specific gene mutations or with a family history of malignancies connected to abnormalities in the BRCA gene. This is done, albeit infrequently, to determine whether the kid has a cancer predisposition syndrome that puts him or her at risk for developing other illnesses or forms of cancer.

Medulloblastoma and other CNS embryonal tumors typically have unknown causes.

Embryonal Tumors: Diagnosis

The diagnosis of the embryonal tumors is mainly done based on history and some of the tests may be required for confirmation and to rule out underlying causes

A study of the patient's medical history and a discussion of the signs and symptoms normally come first in the diagnosing procedure. The following techniques and tests are used to identify embryonal cancers, however further testing might be required to determine whether the malignancy has spread.

• Neurologic examination. Vision, hearing, balance, coordination, and reflexes are assessed during this treatment. This aids in identifying the region of the brain that the tumor may damage.

• Image-based exams. The location and size of the brain tumor can be determined with the use of imaging studies. These tests are crucial for determining if the CSF channels are under strain or blocked. Right away, a magnetic resonance imaging (MRI) or computed tomography (CT) scan may be performed. Brain cancers are frequently identified with these techniques.

• Advanced methods like magnetic resonance spectroscopy and perfusion MRI may also be employed.

• Tissue removal for testing (biopsy). Before the tumor is surgically removed, a biopsy is often not performed, although it can be advised if the imaging findings are unusual for embryonal tumors. To identify the different cell types in the suspicious tissue sample, a lab analysis is performed.

• The sampling of cerebrospinal fluid (lumbar puncture). This technique, also known as a spinal tap, involves placing a needle between two lower back bones to drain the cerebrospinal fluid that surrounds the spinal cord. To check for tumor cells or other anomalies, the fluid is examined. Only after lowering the pressure in the brain or eliminating the obstruction is this test performed.

Embryonal Tumors: Treatment

The treatment is based on the severity of the symptoms. Your doctor may advise conservative or surgical treatment.

• Surgery to remove the excess fluid in the brain. Certain embryonal tumors may develop to obstruct the movement of cerebrospinal fluid, which might result in a build-up of fluid and put pressure on the brain (hydrocephalus).

• Tumour removal with surgery. A pediatric neurosurgeon (brain surgeon) takes off as much of the tumor as they can while being careful not to damage any neighbouring tissue. All children with embryonal tumors should often have further therapies following surgery to focus on any residual cells.

• Radiation treatment. A pediatric radiation oncologist uses high-energy beams, such as X-rays or protons, to provide radiation treatment to the brain and spinal cord to eradicate cancer cells.

• The use of proton beam treatment, as opposed to conventional radiation therapy, allows for the delivery of greater focused doses of radiation to brain tumors while reducing radiation exposure to neighbouring healthy tissue.

• Chemotherapy. Drugs are used in chemotherapy to destroy tumor cells.

Embryonal Tumors: Prevention

Unfortunately, embryonal tumors cannot be prevented.

Conclusion

Embryonal tumors are a group of physiologically diverse diseases with a shared propensity to spread throughout the nervous system through pathways involving cerebrospinal fluid (CSF). Even though there is a great deal of variation, these tumors are grouped histologically because they contain at least a portion of hyperchromatic cells—blue cell tumors on standard staining—that are tightly packed, exhibit a high level of mitotic activity, have little cytoplasm, and are hyperchromatic.

These tumors can be somewhat differentiated from one another using other histological and immunohistochemical characteristics, such as the degree of apparent cellular change along distinguishable cell lineages (ependymal, glial, etc.). Yet, a convention that has been approved by the WHO also distinguishes between these cancers based on their alleged origins in the central nervous system (CNS).

The distinctions between tumors originating in various regions of the brain have been supported by molecular investigations, which lend some support to this system of categorization.