astrocytoma

Astrocytoma: description

The disease is assigned as a brain tumor to the glioma, as it emerges from supporting tissue of the nervous system. It is the most common glioma with a share of more than 60 percent.

The World Health Organization (WHO) divides astrocytomas into four severity levels:

• Grade I: Pilocystic astrocytoma
• Grade II: diffuse astrocytoma
• Grade III: Anaplastic astrocytoma
• Grade IV: glioblastoma

Both the treatment and the prognosis are based on this classification. Glioblastoma is the most common form of astrocytoma with three new cases per 100,000 inhabitants per year. It is six times more common than the diffuse and about ten times more common than an anaplastic or a pilocystic astrocytoma.

Pilocystic astrocytoma

This type of tumor is the most common brain tumor in children, but also occurs in young adults. Mostly it grows in the area of ​​the anterior visual pathway, the hypothalamus or the cerebellum. It is well separated from healthy brain tissue and grows slowly. Thus, this type of tumor is considered to be benign – extremely rarely does it turn into a malignant tumor.

Diffuse astrocytoma

This type of tumor occurs mainly in adults between the ages of 30 and 40 years. It is usually found in the marrow of the cerebrum, the white matter, and grows irregularly in the adjacent tissue. However, it also increases only slowly.

The diffuse astrocytoma is still regarded as a limited benign, although it can almost never be cured. Over time it can become an anaplastic type or a glioblastoma.

Anaplastic astrocytoma

Anaplastic astrocytoma preferably affects adults between 35 and 45 years. It consists of degenerated (anaplastic) cells that usually grow relatively quickly. This tumor can either emerge from the diffuse type or arise directly. He usually degenerates after a few months to years and passes into a glioblastoma.

glioblastoma

Glioblastoma, the most common type of astrocytoma, can either result from another astrocytoma – then the peak age of the patient is between the ages of 50 and 60 years. Or a primary “de novo” glioblastoma develops. This affects mainly older people in the sixth to seventh decade of life.

glioblastoma

Further information on glioblastoma can be found in the article Glioblastoma.

Astrocytoma: symptoms

The symptoms of astrocytoma depend on its exact location in the brain and its size. A pilocystic astrocytoma often grows along the visual pathway causing visual disturbances. If, however, it damages the thalamus, hormonal disturbances can occur. If the tumor is located in the cerebellum, it can lead to coordination problems, a changed language and hand shaking.

Fast-growing tumors not only displace individual brain structures, but also increase intracranial pressure. As a result, sufferers may suffer from headaches, nausea and vomiting. In principle, an astrocytoma causes similar symptoms as other brain tumors.

Brain Tumor – Symptoms

For more information about brain tumor symptoms, read the article Brain Tumor Symptoms.

Astrocytoma: causes and risk factors

An astrocytoma comes from so-called astrocytes. These cells make up the largest proportion of the supporting cells (glial cells) in the central nervous system. They separate the nerve tissue from the brain surface and the blood vessels. Just like other cells in the body, astrocytes are regularly renewed. This can lead to errors that lead to uncontrolled cell growth and ultimately to a tumor.

Why an astrocytoma develops is so far only insufficiently clarified. The only assured risk factor is ionizing radiation. People are usually only exposed to harmful radiation doses as part of radiotherapy.

In addition, this form of brain tumor occurs frequently in certain underlying diseases. These include neurofibromatosis type I (Recklinghausen’s disease) and type II, tuberous sclerosis (Bournville-Pringle’s disease), Li-Fraumeni syndrome and Turcot’s syndrome. These diseases are very rare and are usually associated with typical changes in the skin.

Astrocytoma: examinations and diagnosis

The right person to contact if you suspect an astrocytoma is the neurologist. He asks the person concerned exactly according to his complaints, any pre- and underlying diseases and his life circumstances (collection of medical history = history). He then initiates the further diagnostic steps and examinations.

The most important diagnostic procedure in an astrocytoma is magnetic resonance imaging (MRI) – an imaging technique that uses magnetic fields and electromagnetic waves to produce accurate cross-sectional images of the interior of the body. Often people are injected with a contrast agent into a vein before the examination. Astrocytomas absorb the contrast agent differently. This creates a luminous area in the picture. A pilocystic astrocytoma illuminates strongly and evenly, while a diffused or anaplastic astrocytoma usually does not absorb any or only little contrast and appears rather dark. In contrast, a glioblastoma forms a characteristic annular structure with contrast agent.

If MRI can not be performed for a variety of reasons, computed tomography (CT) is used as an alternative.

In a grade II or higher astrocytoma, a tissue sample should be taken and examined in the laboratory. In addition, further examinations may be indicated in individual cases, such as a removal and analysis of cerebrospinal fluid (cerebrospinal fluid) (CSF diagnostics) or a measurement of electrical brain energy (EEG).

Overall, in an astrocytoma in principle the same medical and instrumental examinations are performed as in other brain tumors.

Astrocytoma: treatment

In general, this form of brain tumor can be operated on, stained and treated with special drugs (chemotherapeutic agents). If a pilocystic astrocytoma is present, surgery is usually sufficient. Other treatment options are only used if the tumor could not be completely removed. A diffused astrocytoma, on the other hand, can almost never be completely removed by surgery. If residual tumor remnants begin to grow again, they are usually irradiated.

In circumscribed tumors also a brachytherapy can be performed. For this small radioactive granules (seeds) are implanted in the affected body region. The advantage of this form of irradiation is that it hits the tumor in a very targeted manner, thus damaging less healthy tissue.

If the astrocytoma increases further under radiation, chemotherapy may be considered. Anaplastic astrocytoma is usually irradiated immediately after surgery or treated with chemotherapeutic agents.

In addition to these therapeutic measures, there are still numerous treatment measures that, although not the tumor itself, but combat the symptoms. Thus, various medicines for headache, nausea and vomiting can be administered. In addition, those affected can take professional psychotherapy or pastoral care.

Hirtumor – examination

More detailed information on examination and treatment can be found in the article Brain Tumor.

Astrocytoma: disease course and prognosis

Disease course and prognosis differ between the individual forms of astrocytoma:

A pilocystic astrocytoma can be long-term cured at a complete surgical removal. If the tumor is close to important brain structures such as the visual pathway, surgery is not always possible. The prognosis of alternative radiotherapy or chemotherapy is slightly worse. However, five years after the diagnosis, 94 percent of all patients still live with this tumor type.

In contrast, a WHO grade II or III astrocytoma has a significantly worse prognosis. Although second- and third-degree astrocytomas can usually be treated surgically, they often return (recurrences). Both can also malignantly degenerate into a glioblastoma (grade IV). This has the worst prognosis: Five years after diagnosis, only five percent of those affected live.

Thanks to good supportive therapeutic measures, patients’ quality of life has improved astrocytoma improved.