Primitive neuroectodermal tumor is a tumor in the tissue of the nerves. The disease is one of the embryonal tumors and is referred to by the abbreviation PNET. The primitive neuroectodermal tumor occurs in the majority of cases in childhood and adolescence. In principle, a distinction is made between tumors of the central nervous system and peripheral forms.
What is a primitive neuroectodermal tumor?
In principle, two different forms of primitive neuroectodermal tumor exist. Primitive neuroectodermal tumor of the central nervous system was first described in 1973. On the histological level there are some similarities between the primitive neuroectodermal tumor and so-called pinealoblastomas and medulloblastomas. Some physicians summarize this category of tumors as embryonal tumors of the central nervous system. However, controversy exists among researchers in this regard. Approximately two to six percent of brain tumors that occur in children and adolescents are primitive neuroectodermal tumors. Peripheral primitive neuroectodermal tumors represent the second type. These usually form from tissues that serve an ectodermal derivation function. These primarily include the autonomic nervous system, consisting of the parasympathetic and sympathetic nervous systems. The peripheral variant of the tumor arises particularly frequently on the thoracic wall. The exact name for tumors with this localization is Askin tumors. In addition, the tumors are also found on the uterus and ovary, testis and urinary bladder, and lungs and kidneys. Sometimes they also affect the salivary glands of the abdomen and ear, as well as the skin. When diagnosed, it is often difficult to distinguish them from so-called Ewing’s sarcomas.
Causes
The exact causes of growth and development of primitive neuroectodermal tumors are not well understood with regard to current research. Presumably, there is an interplay between various factors in disease genesis, although genetic influences are also possible.
Symptoms, complaints, and signs
The specific symptoms of primitive neuroectodermal tumor depend primarily on the location of the tumors. Primitive neuroectodermal tumors in the central nervous system area, for example, are noticeable by vomiting and nausea. These signs are most apparent in the morning, when individuals have an empty stomach. In addition, other, more serious symptoms are possible. In some patients, certain abilities are lost and paresis or impaired vision occur. Sometimes even changes in the personality of the affected patient occur. The symptoms of primitive neuroectodermal tumor in the central nervous system result from neurological lesions and deficits when functions of nerves are lost. If the primitive neuroectodermal tumors are located inside the body, other symptoms usually appear. For example, when the lungs are affected, patients suffer from bloody cough and shortness of breath. Primitive neuroectodermal tumors of the uterus or pancreas initially cause pain in the abdomen.
Diagnosis and disease progression
Diagnosis of primitive neuroectodermal tumor is a lengthy process in many cases. Basically, primitive neuroectodermal tumor is often diagnosed relatively late because the symptoms tend to be nonspecific. If persons show corresponding symptoms, they first consult their family doctor. This physician will usually refer the patient to a specialist who will perform further examinations. At the beginning of the diagnostic process, the physician obtains information about the patient’s symptoms and the onset of the complaints, as well as information about possibly decisive circumstances. It is also important to take a family history, since similar cases in the family strengthen the suspicion of a particular disease. During the clinical examination, the treating specialist uses various methods to diagnose the primitive neuroectodermal tumor. Using imaging techniques, the physician examines the tumor and surrounding areas. He usually uses ultrasound techniques as well as CT or MRI procedures. In this way, indications of the size and extent of the tumor can be obtained. However, imaging alone cannot provide a reliable diagnosis.A biopsy usually provides particularly important information. Here, the physician removes tissue from the corresponding area and orders a histological analysis of the sample. In some cases, such a biopsy is only possible after the tumor has been removed. In primitive neuroectodermal tumors in the central nervous system, on the other hand, histologic examination is often not feasible.
Complications
Because this disease is a tumor, its subsequent course and complications depend greatly on the timing of its diagnosis. In particular, early diagnosis has a positive effect on the life expectancy of those affected. Patients themselves suffer from permanent nausea and vomiting with this cancer. Especially in the morning, these symptoms can increase and significantly reduce the quality of life of those affected. Furthermore, there is also loss of various motor skills. As the disease progresses, those affected sometimes suffer from paralysis and visual problems. Personality changes may also occur with this tumor, leading to severe depression or other psychological problems. Furthermore, patients suffer from coughing and shortness of breath. This usually causes the patient to be tired and fatigued as well. The treatment of this tumor is done with the help of surgery and chemotherapy. Although there are no complications, the tumor may have already spread to other regions of the body. Possibly, the patient’s life expectancy is reduced.
When should you see a doctor?
If symptoms such as nausea and vomiting, paralysis, or neurologic deficits occur repeatedly, there may be an underlying primitive neuroectodermal tumor. A visit to the physician is indicated if symptoms persist over a period of several days or rapidly become more severe. If symptoms such as swelling, shortness of breath or coughing up blood are also present, the patient must see a doctor the same day. People who have already suffered from a brain tumor once are best advised to consult the neurologist in charge. The physician can determine the primitive neuroectodermal tumor by means of a fine tissue examination. Treatment can then be initiated, which offers good chances of cure if detected early. If unusual symptoms occur that may be associated with a brain tumor, the primary care physician should be contacted first. In case of a concrete suspicion, the neurologist is the right contact person. Depending on the symptom picture, internists, ENT physicians and physiotherapists may be involved in the treatment. In addition, nutritionists and alternative physicians may be part of the therapy of a primitive neuroectodermal tumor.
Treatment and therapy
The primitive neuroectodermal tumor is removed when possible and then undergoes detailed histologic examination. Resection is much easier in primitive neuroectodermal tumors of a peripheral nature than in those of the central nervous system. After the removal of tissue or following a surgical intervention, the affected children and adolescents receive a so-called polychemotherapy. This involves the administration of various cytostatic drugs. In addition, patients usually undergo radiotherapy. The prognosis of the primitive neuroectodermal tumor depends on the localization, the age of the affected person and the possibility of surgical removal. On average, approximately 53 percent of patients survive the five-year period.
Prevention
Targeted prevention of primitive neuroectodermal tumor is not yet possible because the causes are not well understood. Therefore, timely diagnosis is particularly important for patients.
Follow-up
After therapy of a primitive neuroectodermal tumor, intensive follow-up care is required. For example, the actual treatment by surgery, chemotherapy, or radiotherapy carries an increased risk of side effects. These can manifest themselves both physically and psychologically. Often they only become apparent after the treatment has been completed. Another important part of aftercare is the early detection of a possible recurrence, in which the tumor shows itself again. Therefore, after the end of treatment, the patient must undergo regular
regular check-ups after the end of treatment. In this way, any relapse can be detected in good time and treated accordingly.Follow-up care takes plenty of patience and extends from childhood and adolescence into adulthood. This is true even if there is no visible residual tumor. The first physical examination takes place around six weeks after the end of tumor therapy. In the first two years, this is usually done every six to eight weeks. Later, the examination intervals increase. Primarily, imaging procedures such as magnetic resonance imaging (MRI) of the brain and spinal cord are used. Further imaging examinations are performed every three to four months during the first two years. Eye and ear examinations are also performed to detect possible late effects. Electroencephalography (EEG) may also be useful to check brain function.
Here’s what you can do yourself
The tumor develops primarily in children and adolescents. Since they are naturally not yet able to do sufficient research on the disease they have suffered, doctors as well as relatives should inform the offspring extensively and keep them informed about further developments. Questions and uncertainties should be answered honestly so that no complications or misunderstandings arise. If the relatives feel overwhelmed by the situation, they should seek help themselves. In addition, it should be checked whether the patient also needs psychotherapeutic support. This can help to cope better with the challenges in everyday life. One of the possible complaints of the disease is shortness of breath. This can lead to anxiety or panic reactions. The affected person must be educated on how to behave optimally in the event of a reduced oxygen supply. These tips can be life-saving in acute situations. Therefore, they should be sufficiently practiced and trained in advance. To strengthen the mental power, the joy of life and the well-being are to be promoted. Recreational activities are to be individualized according to the wishes of the child as well as the needs of the organism. A stable environment is important in coping with the disease. Stress and other disturbing factors can trigger further psychological problems in severe cases.
