How Anaplastic Astrocytoma Is Diagnosed

As with other kinds of brain tumors, a diagnosis of anaplastic astrocytoma is based on a variety of different methods, including detailed patient history, a variety of imaging techniques, and, in some cases, a brain biopsy.

This article discusses these different procedures and outlines other conditions that may be confused with this rare brain tumor.

Self-Checks

As anaplastic astrocytoma is located in the brain, there are generally few changes you will be able to see on your own. However, there are a few signs of this type of tumor that you should be aware of, especially because they can be subtle and take a while to develop. 

Be sure to take note of any of the following and bring them to the attention of your doctor:

• Headaches: Brain tumor headaches tend to have distinct characteristics or are combined with other symptoms, like vomiting. They are usually dull and persistent, with throbbing headaches occurring less often.
• Vomiting: This is most common in the morning, and is often triggered by a sharp movement, such as rolling over in bed. 
  
• Changes in personality: Brain tumors can cause someone to experience personality changes, such as laughing at inappropriate times and engaging in risky behavior. Typical personality traits may also become exaggerated.
• Changes in mood: Signs of a brain tumor have also been known to mimic those of depression.
• Drowsiness: The pressure that the tumor puts on the brain can cause a person to become progressively more fatigued, even to the point of unconsciousness.

Seizures are a common symptom for many brain tumors, but they are less common in people with anaplastic astrocytoma.

Physical Examination

A physical exam can help your doctor determine whether you have a possible brain tumor, such as anaplastic astrocytoma.

Anaplastic astrocytomas are normally located in two cerebral hemispheres of the brain. Depending on where the tumor is in the brain, there may be signs that can be noticed in a physical exam. These may include coordination problems or weakness in the arms and legs.

Your eyes may also be examined to see if there is swelling caused by increased pressure in the brain caused by a tumor.

Your doctor will also take a detailed patient history. Anaplastic astrocytomas are not usually inherited, but they may have a genetic link when they are associated with a few rare, inherited disorders, including:

• Neurofibromatosis type I, which causes tumors to grow along your nerves
• Li-Fraumeni syndrome, which increases your risk of having rare cancers
• Turcot syndrome, causes the formation of multiple benign growths, or polyps, in the colon in association with a primary brain tumor
• Tuberous sclerosis, is a condition that causes benign growths in the brain and other organs
  

Imaging

Imaging assesses the size of a tumor and its location within the brain, as well as characteristics that help differentiate one type of tumor from another. These techniques may also serve as an aid for future surgical procedures.

Computerized tomography (CT) scans and magnetic resonance imaging (MRI) are the imaging tests most commonly used to diagnose anaplastic astrocytoma.

CT Scans

A CT or CAT scan involves the use of multiple X-ray images that are then put together to form a 3D image.

During a CT scan, you will need to remain still so that the images can be captured. If you need to sneeze or itch or you are cramping up, let the technician know. There is no problem with stopping the test momentarily.

Unlike old CT scanners, newer units only emit slight buzzing, whirring, or clicking sounds, and you will feel no pain from the scan itself.

MRI

MRI uses a magnetic field and radio waves to produce images of organs or bodily tissue. The MRI will usually be used along with a contrast material, such as gadolinium. This material is a fluid that surrounds solid areas, such as brain tumors, to better define the edges. 

An MRI can be very noisy, so do not be alarmed when you hear a clanging noise during the test. This is caused by some of the magnets in the machine.

Advanced imaging techniques may also be used to help in the diagnosis of anaplastic astrocytoma:

• Diffusion-weighted MRI imaging
• Magnetic resonance spectroscopy
• Magnetic resonance perfusion
• Amino acid positron emission tomography imaging
  

Labs and Tests

Based on the results of the imaging studies, further tests may be used to find out more about the tumor.

Biopsy

The diagnosis of anaplastic astrocytoma can be confirmed by the surgical removal and microscopic evaluation of a small part of the tumor. This is known as a biopsy.

A biopsy is also used for grading primary brain tumors on a scale from I to IV. Low-grade brain tumors are considered less aggressive than high-grade ones. Anaplastic astrocytomas are Grade III.

A biopsy can also determine how sensitive the tumor will be to different types of treatments. This can help guide your doctor's recommendations on the best line of care. 

A brain tumor biopsy is an invasive procedure that requires surgery under general anesthesia. It usually involves the removal of a section of the skull to access the brain tissue. It can take several weeks to recover from a brain biopsy, even if the sample is small. There is a risk of bleeding or swelling in the brain, so you will be closely monitored after the procedure.

Genetic Testing

While most anaplastic astrocytomas are not associated with an inherited condition, genetic testing is available for those genetic disorders that are associated with an increased risk of developing this type of tumor.

A genetic test involves obtaining DNA from a sample of cells in your body to identify specific genes, chromosomes, or proteins. Several hundred genetic tests are currently available, with many more being developed.

Genetic tests can be performed on blood, urine, saliva, body tissues, bone, or hair.

Differential Diagnoses

A diagnosis of anaplastic astrocytomas requires that it is distinguished from other types of brain tumors. These include:

• Metastatic tumors
• Lymphomas
• Hemangioblastomas
• Craniopharyngiomas
• Teratomas
• Ependymomas
• Medulloblastomas

Anaplastic astrocytoma can also cause symptoms similar to those of other conditions. The procedures outlined above can differentiate between this type of brain tumor and other conditions, such as:

• Meningitis: This is an inflammation of the membranes and fluid that surround the brain and spinal cord. There are two main types meningitis: viral and bacterial.
  
• Pseudotumor cerebri: This occurs when the pressure within the skull, or intracranial pressure, increases for no apparent reason. This increased pressure causes symptoms of a tumor in the brain, but because there is no tumor present, the condition is referred to as a pseudotumor or false tumor. 

Summary

A diagnosis of anaplastic astrocytoma can only be made following an imaging procedure, such as an MRI or CT scan, along with, in some cases, a brain biopsy, the remova,l and evaluation of the tumor's tissue.

While there are signs that may indicate the existence of this type of brain tumor, they are not sufficient for a diagnosis. Because other conditions share many of the same symptoms as anaplastic astrocytoma, they should be ruled out before a diagnosis is made.

A Word From Verywell

It can be very distressing to experience the signs and symptoms outlined above, and it is natural to worry that you may have a brain tumor. Talk to your doctor as soon as you experience any of these symptoms. And remember, a diagnosis can only be made following a thorough clinical evaluation.