A thymoma is a rare tumor of the mediastinum that originates from the thymus and is benign in most cases. Men and women are equally likely to be affected by thymoma. The tumor is usually well treatable, and a thymoma is usually surgically removed as part of a resection.
What is a thymoma?
Thymoma is the name given to a rare tumor disease of the thymus, which in most cases (about 75 percent) is classified as benign. The thymus is located near the heart, in the anterior region of the mediastinum and, as the primary organ of the lymphatic system, is important for the development and differentiation of certain T lymphocytes in childhood. Symptoms characteristic of thymoma, such as cough, feeling of pressure, dysphagia (difficulty swallowing), dysfunction of the heart, hoarseness, or shortness of breath, usually do not manifest until the later stages of the disease, when the thymoma’s size constricts and damages neighboring structures, especially the esophagus and trachea.
Causes
The causes of malignant (malignant) thymoma or thymic carcinoma have not yet been clarified. The only certainty is that the tumor arises from a degenerate cell that multiplies and damages surrounding structures by growing. In addition to genetic factors, certain environmental factors such as pollutants and toxins as well as irradiation are discussed as triggers for this degeneration process. In contrast, benign thymomas are in many cases associated with certain diseases. For example, myasthenia gravis (autoimmune disease) occurs together with a thymoma in about 20 to 40 percent of cases, although the exact relationship between these diseases has not been clarified. It is suspected that the dysregulated antibodies that attack the body’s own muscle cells in myasthenia gravis may originate from the thymus. In addition, anemia (pur red cell aplasia), hypogammaglobulinemia (lack of antibodies), polymyositis (inflammation of skeletal muscle), thyroiditis (inflammation of the thyroid gland), and Sjögren’s syndrome (autoimmune disease) are associated with benign thymoma.
Symptoms, complaints, and signs
Affected individuals usually do not present symptoms to a physician until the disease has progressed. Symptomatically, the tumor displaces or grows into another tissue. Initially, signs are sometimes misinterpreted. Conventional medications then remain ineffective and do not promise a cure. Depending on the location of the thymoma, different symptoms result. If the tumor presses on the esophagus, patients complain of difficulty swallowing. If shortness of breath occurs, the trachea is usually constricted. A persistent cough is then also encountered. In both cases, sufferers regularly report pressure in the chest area. If, on the other hand, persistent hoarseness is noticeable, this is usually due to paralysis of the cervical nerves. If the tumor attacks the heart, life-threatening functional disorders are imminent. The characteristic effects are accompanied by general phenomena resulting from the weakening of the organism. Basically, diseased persons tire unusually quickly without having previously exerted themselves physically. The body is susceptible to illness, which upsets everyday life and requires adherence to hygienic standards. Weight is not infrequently reduced within a few months. The he|muscle strength decreases. Longer walks can become a torment. Sudden dizziness threatens in all places.
Diagnosis and progression
The diagnosis of a thymoma is made on the basis of characteristic symptoms during a medical history and physical examination. The diagnosis is confirmed by imaging procedures such as an X-ray examination, an MRI (magnetic resonance imaging) or CT (computed tomography). Imaging procedures can also provide information about the localization, size, stage as well as impairment of surrounding tissue structures. A biopsy with subsequent histological (fine tissue) analysis, which serves to differentiate between malignant or benign thymoma, is usually performed only in the course of surgical tumor resection (removal of the tumor), since the thymus is located in an unfavorable position and is difficult to access. As a rule, the course and prognosis of both benign and malignant thymoma are good, depending on the time of diagnosis and stage of the tumor disease, and about 90 percent of those affected are still alive five years after diagnosis.
Complications
Tumor diseases of the thymus are benign in about three-quarters of all cases. If treated promptly, complications are usually not expected. However, recurrence cannot be ruled out. Since thymomas are slow-growing tumors, it can take up to ten years for the tumor to return after treatment that appears successful. Patients must therefore attend regular check-ups over long periods of time. If the tumor is not treated in time, the typical symptoms such as shortness of breath, chest pain and heart problems often take on very severe forms and considerably impair the patient’s quality of life. Moreover, if the tumor is discovered too late, it is not uncommon for its size to be reduced by means of chemotherapy before surgery can be performed. Chemotherapy is often accompanied by a number of very unpleasant side effects, particularly nausea, vomiting and loss of scalp hair. Radiation can damage the heart or lungs in isolated cases. Furthermore, complications can occur if the tumor grows into surrounding organs or metastases form. The latter is particularly dangerous in the rather rare malignant thymomas. In these cases, chemotherapy or radiation therapy is almost always required. Deaths are rare but cannot be completely ruled out.
When should you see a doctor?
If there is a steady increase in malaise, a feeling of illness, and internal lassitude, a doctor should be consulted. If there is a decrease in physical strength, a loss of mental capacity as well as a reduced ability to cope with stress, clarification of the cause is advisable. General dysfunction, general weakness, increased need for sleep, and irregularities in heart rhythm should be investigated and treated. Headaches, hoarseness, restrictions in breathing or swallowing are signs of a health disorder. If muscle strength decreases, daily responsibilities can no longer be performed, or the affected person experiences a restriction in performing the usual sporting activities, action is required. Heart palpitations, dizziness, restrictions in movement and fatigue are further signs of a present illness. If the affected person suffers from changes in the appearance of the skin, hoarseness or increasing psychological problems and behavioral abnormalities, a doctor should be consulted. If the zest for life decreases continuously over a longer period of time, if there is a withdrawal from social and societal life or if the affected person suffers from rapid irritability, the observations should be discussed with a doctor. In many cases, emotional and mental problems indicate the presence of a physical impairment. Extensive investigations are necessary to determine the cause of the complaints.
Treatment and therapy
Therapeutic measures for a thymoma depend on the stage of the disease. If a small thymoma limited to the thymus is present, the tumor with the surrounding conspicuous lymph nodes and the adjacent connective and fatty tissue are surgically removed (resection). In the more advanced stages of a thymoma, additional radiotherapeutic measures are used to prevent recurrence (recurrence of the tumor). In some cases, such as in the presence of metastasis (9 percent of cases) or very poor general condition of the affected person, chemotherapeutic measures are also used. Even in the case of large thymomas, the tumor can first be reduced in size in the course of chemotherapy before it is surgically removed. In affected individuals in whom resection is ruled out and chemotherapeutic and/or radiotherapeutic measures have been unsuccessful, in some cases a combination therapy with a somatostatin analogue (synthesized growth hormone), which intervenes in tumor development and delays its growth, and cortisone is indicated. However, this therapeutic approach is still being explored in clinical trials. Regular follow-up and control examinations using imaging techniques, as well as blood tests for early detection and treatment of recurrences, are essential components of successful thymoma therapy because thymomas have a high local recurrence rate.
Prevention
Because the causes of thymoma are not understood, no preventive measures exist to date.Affected individuals with diseases with which thymoma is associated (especially myasthenia gravis) should be monitored early for underlying thymoma.
Follow-up
Thymomas can be both benign and malignant. For this reason, regular follow-up after the actual treatment is exceedingly important. It should also be noted that the local recurrence rate of thymomas is high. Thus, new manifestations of the tumor can still occur ten years after surgical removal, which makes long-term monitoring necessary. Among the most common secondary tumors or second cancers is non-Hodgkin’s lymphoma, which not infrequently presents after a thymoma. Follow-up care for thymoma after cancer treatment is completed includes check-ups that take place at regular intervals. During this process, the physician performs imaging examination procedures. Blood tests are also performed. In this way, possible recurrences can be diagnosed at an early stage and treated accordingly. During the follow-up period, the patient attends a check-up every three months for the first two years. During this checkup, the physician will review the patient’s medical history and perform a thorough physical examination. At 12-month intervals, it is also recommended that a computed tomography (CT) scan of the thorax (chest) be performed. In this way, local recurrences can be effectively detected with these procedures. It is recommended that follow-up examinations be performed by the thoracic surgeon who was previously responsible for treating the tumor. In addition, in the case of proven myasthenia, examinations should be performed by a neurologist.
What you can do yourself
For patients with thymoma, medical treatment and care are the first priority. Self-care measures can support medical interventions but should not remain the sole means. Adequate medical therapy is of utmost importance in the presence of a thymoma, since in some cases the disease is malignant in nature and thus poses a threat to the life of the affected person. Therefore, it is in the interest of patients with thymoma to undergo all offered check-ups with various specialists and to actively participate in the treatment of the disease. For example, prescribed medications should be taken exactly as prescribed and any side effects should be reported to the physician immediately. In some cases, removal of the thymoma, and sometimes the entire thyroid gland, is necessary. This is especially necessary if the tumor is malignant and in an advanced stage. Patients prepare for this operation in the best possible way by taking care of themselves physically and mentally, avoiding stress, following a healthy diet and avoiding stimulants such as cigarettes and alcohol. They also take care to take it easy on themselves physically after the surgical procedure and undergo all check-ups and follow-up examinations with their doctor so that any complications can be treated in good time.
