The term "mediastinal thymoma" refers to a tumor process that occurs in the thymus gland. The latter plays an important role in the formation of the body's defense system in children, while in adults it usually atrophies. Nevertheless, thymoma is most often diagnosed in people of mature and advanced ages. According to statistics, this kind of neoplasm is detected in 8% of children. A tumor of the anterior mediastinum is a threat not only to health, but also to the life of the patient. This is due to the fact that against the background of growth of the neoplasm, compression of blood vessels, heart, lungs occurs.
Development mechanism
Not everyone knows that the mediastinum is such a collective term for a group of organs located between the pleural cavities. In its upper part is the thymus gland (its other name is the thymus). This is an organ consisting of two asymmetric lobes. Each of them is represented by many particles from the brain and cortex.
Thymus is not only an organ of the immune system, but also an endocrine gland. After about 20 years, his age-related involution occurs. About 90% of the organ is replaced by connective and adipose tissue. Despite this, under the influence of various unfavorable factors, the process of the development of a neoplasm - mediastinal thymomas can start. Its gradual growth leads to compression of vital organs and blood vessels. The complexity of the treatment lies in the fact that in most cases, patients seek medical help at a late stage of the disease.
The development of a neoplasm can occur from any tissue. In this regard, the following types of thymoma are distinguished:
- Lymphoepithelial.
- Spindle cell.
- Lipotymoma.
- Epidermoid.
- Lymphoid.
- Granulomatous.
According to the International Classification of Diseases (ICD-10), the mediastinal thymoma has a code of C38.
Causes
It is currently unknown why the development of thymus tumors occurs. It must be remembered that the mediastinum is such a concept that means a group of organs, and therefore, there can be many provoking factors.
Doctors tend to believe that in most cases the tumors are of embryonic origin. In addition, the following diseases and conditions can be the causes of the development of mediastinal neoplasms:
- Pathologies of an infectious nature.
- Violation of the production of thymopoietin.
- Radiation effect on the body.
- Impaired immune homeostasis.
- Injuries to the mediastinum.
In addition, it was noted that thymomas often occur in the presence of autoimmune and endocrine syndromes.
Symptoms
In half of the patients, the tumor is small and is not accompanied by severe clinical manifestations. In most cases, the neoplasm is detected randomly during a routine x-ray examination.
As the mediastinal thymoma grows, its first signs begin to appear. They are divided into those that are associated with compression of nearby organs, and those that are caused by a malfunction of the gland itself.
In the anterior mediastinum are located: bronchi, trachea, ascending aorta, pulmonary and superior vena cava, lymph nodes, arteries and phrenic nerves. When they are squeezed, the patient has the following symptoms:
- Cough.
- Dyspnea.
- Squeezing in sternum.
- Swelling of the face.
- Cyanosis of the neck.
- Hoarseness in voice.
- Swelling of veins located on the neck.
The clinical picture with hormonal disorders is more pronounced. In such cases, the following symptoms of mediastinal thymoma occur:
- Myasthenia gravis (atrophy of muscle tissue).
- Signs of anemia.
- Obesity.
- Hypertension.
- Hirsutism in women and gynecomastia in men.
In addition, against the background of thymoma, osteoporosis and diabetes develop. If the neoplasm is malignant, patients complain of: general weakness, weight loss, pallor of the skin, impaired appetite, and insomnia. With tumor metastasis, pain occurs in the limbs and spine.
Severity
In practice, the classification of thymoma is used in order to determine the desired volume of therapeutic measures. The tumor has the following stages of development:
- I. The neoplasm is enclosed in a dense capsule on all sides. The tumor is small. At this stage, the prognosis is favorable, since the disease is easily treatable.
- II. It is characterized by the presence of tumor elements in adjacent fatty tissue and the pericapsular zone. At this stage, conservative methods of therapy are ineffective, only surgical intervention is advisable.
- III. Thymoma elements sprout into nearby mediastinal tissue. In such cases, chemotherapy and surgery are indicated.
- IV. The stage is characterized by metastasis of the tumor through lymph and blood circulation. In such situations, a course of chemotherapy is indicated.
Thus, with a timely visit to the doctor, the prognosis is most favorable. Treatment of mediastinal thymoma at an early stage in most cases is successful and does not lead to serious consequences.
Benign neoplasms
They account for 50 to 70% of thymus gland tumors. Externally, thymoma has the appearance of an encapsulated node. Its diameter does not exceed 5 cm. Depending on histogenesis, the tumor may have the following types:
- Type A. Its other name is medullary. It accounts for up to 7% of the benign nature. A tumor always has a capsule. With adequate treatment for mediastinal thymoma, the prognosis is favorable, survival in the next 15 years is 100%.
- Type AB. Another name for the tumor is cortico-medullary. It is diagnosed in a third of patients. The forecast is satisfactory. Survival over the next 15 years is 90% or more.
- Type B1. It occurs in 20% of cases. It is accompanied by lymphocytic infiltration and often myasthenic syndrome. The prognosis for such a thymoma is satisfactory. Survival over the next 20 years is 90% or more.
Type 1 malignant tumor
It accounts for 20 to 25% of cases. Timoma is represented by a single node or multiple neoplasms. They do not have a clear capsule. Typically, the diameter of the thymoma is not more than 5 cm, but large tumors are also found.
In histology, it is customary to isolate cortical (type B2) and epithelial (B3) tumors. In both cases, the prognosis is poor. Less than 60% of patients live another 20 years with cortical thymoma, no more than 40% with epithelial.
Type 2 malignant tumor
Similar thymus disease accounts for up to 5% of patients. In such cases, cancer is accompanied by severe symptoms. Tumor growth occurs extremely quickly, metastases spread throughout the body.
Who to contact
If there are disturbing symptoms, you need to see a local therapist or oncologist. If necessary, the doctor will send for consultation to other narrow specialists. As a rule, not only an oncologist, but also a surgeon, neurologist and endocrinologist are involved in the diagnosis of mediastinal thymoma.
Diagnostics
During the initial appointment, the doctor collects an anamnesis and conducts a physical examination. In the course of the latter, wheezing, wheezing and tachycardia are revealed.
Based on the results of the initial diagnosis, the specialist prescribes a comprehensive examination. It includes the following basic methods:
- Roentgenography. In the presence of thymoma in the image, a volumetric neoplasm that has an irregular shape can be visualized.
- CT scan of the chest. This type of study allows you to get more information regarding the existing pathology. With the help of CT of the chest organs, it is possible to clarify the location of the tumor, evaluate its morphological properties, and also reveal the nature of its interaction with nearby tissues.
- Biopsy. The patient carries out the sampling of biological material - puncture of a small amount of pathologically altered tissue. The sample is then examined under a microscope to determine the type of tumor.
- MRI Allows you to get clear images of the necessary part of the body.
- PAT. The patient is injected with a contrast medium and a series of shots are taken. Cancer cells absorb a large amount of radioactive material, so that they can be detected.
In addition, the doctor conducts differential diagnosis with dermoid cysts, sternal goiter and mediastinal teratoma.
Treatment
There are several options for getting rid of thymoma. The advisability of prescribing a particular method is determined solely by the doctor.
Ways to treat mediastinal thymoma:
- Surgical intervention. During the operation, doctors remove the neoplasm and the surrounding tissue. As a rule, in practice, the most commonly used method is called median sternotomy. Access to the tumor is through an incision in the sternum. In addition, minimally invasive techniques that are video-controlled can be used to treat thymoma. In such cases, the operation is performed through several small incisions in the sternum, into which endoscopic instruments are inserted.
- Radiation therapy. It implies the use of particles with a high energy index. These substances can destroy cancer cells. The most common is the type of therapy in which radiation comes from outside the body, that is, from a special apparatus. As a rule, a course of treatment is prescribed after an operation to remove thymoma. Side effects of radiation therapy: fatigue, skin reactions, digestive disorders. Often, patients complain of difficulty in swallowing food.
- Chemotherapy. This term refers to the use of medications, the active substances of which destroy cancer cells or stop their growth. A chemotherapy course consists of several procedures. The duration of treatment is determined only by the doctor. As a rule, the following drugs are used: Carboplatin, Cyclophosphamide, Etoposide, Paclitaxel. In some cases, chemotherapy is prescribed immediately before surgery to reduce the size of the thymoma. Side effects include the following conditions: hair loss, constant fatigue, nausea, and vomiting. They pass immediately after completion of treatment.
- Maintenance therapy It is an additional treatment method. It is necessary to facilitate the well-being of the patient. In addition, such therapy implies supporting the patient's social, physical, and emotional needs.
General forecast
After treatment of benign thymoma, long-term results are good. Shortly after removal of the neoplasm, unpleasant symptoms disappear, the person's condition improves.
In the presence of malignant thymoma, the prognosis is satisfactory only with timely medical attention. 90% of operated patients live 5 years or more. At stage III of the disease, this indicator is lower - 60-70%. In advanced cases, that is, in the presence of an inoperable tumor, the prognosis is poor. Most patients (90%) die in the next 5 years.
Prevention
There are no specific measures to prevent the development of the disease. This is due to the presence of many provoking factors. In addition, the exact causes of the onset of the tumor are currently unknown.
In the presence of a neoplasm of a benign nature, it is important to prevent its transition to cancer. To do this, you must consult a doctor in a timely manner (if the first alarming symptoms occur) and undergo a treatment course prescribed by a specialist, including both conservative and surgical methods.
Finally
The term "mediastinal thymoma" refers to a tumor process that develops in the thymus gland. This is an organ that in children takes part in the formation of the immune system. Over time, iron undergoes age-related involution. Nevertheless, mediastinal thymoma is most often diagnosed in adults. The main method of treating a tumor is its removal by surgical methods. Additionally, chemotherapy, radiation and supportive therapy can be prescribed.