Timoma is a type of tumor lesion with predominant localization in the thymus gland, which has a benign course and a tendency to malignancy. In connection with the peculiarity of localization of tumor lesion, this pathology in the oncological classifications are still formulated as "thymoma of the mediastinum".
In the pathogenetic mechanisms of the emergence of this pathology, the sex and age of the patient does not matter, however, according to world statistics, thymoma in children is classified as a rare pathology. The risk group for this disease is the elderly, suffering from myasthenia gravis .
In a situation where the tumor substrate contains not only elements of the thymus, but also adipose tissue, conditions are created for the development of lipotymoma characterized by asymptomatic flow.
Causes of thymoma
Thymoma of the thymus gland, as a rule, is a volumetric neoplasm with all the signs of good quality, that is, it has relatively small parameters, is surrounded by a dense shell from surrounding tissues and is characterized by a slow flow.
In some cases, thymomas acquire signs of malignancy, that is, "malignant," with rapid infiltrative growth, the ability to screen out distant metastases and even recur after radical surgical removal.
Pathomorphological features of this type of tumor is the presence of multiple foci of necrosis and hemorrhages, which are subsequently resolved with the formation of cystic structures with a sclerotic component.
Symptoms of thymoma
This pathology belongs to the category of polysymptomatic diseases, since even under equal conditions of its occurrence, individual patients can have an individual clinical picture. In the era of rapid development of technologies in the field of diagnostic studies of certain diseases, conditions are created for the early detection of thymoma, which in the initial stages of development does not have a clear specific symptomatology.
Typical complaints arise in a patient suffering from thymoma, after achieving large neoplasms that exert pressure on other structures of the upper level of the mediastinum. In this period the patient can note the discomfort in the sternum, which is of a permanent nature and has nothing to do with the pain syndrome.
When the cartilage structures of the trachea are compressed, the patient has respiratory disturbances of varying intensity, up to apnea . When the primary objective examination of a patient with thymoma, attracts attention some cyanosis of the skin, pastose in the upper half of the trunk and swelling of the venous vessels in the neck.
In some cases, thymoma may manifest as uncharacteristic symptoms arising from its development against other diseases such as myasthenia gravis, agammaglobulinemia, and Itenko-Cushing syndrome .
All morphological varieties of thyme have a single variant of the course of the disease, which is divided into two phases: asymptomatic and a phase of pronounced clinical and morphological manifestations.
The length of the latent period during which the patient does not feel changes in his state of health and in most cases does not even know about the presence of thymoma is influenced by a number of factors, namely: the location and metric parameters of the tumor, the intensity of proliferation of the tumor substrate, positional relationships with other structures , belonging to this department of the mediastinum.
All clinical manifestations of thymoma can be attributed to this or that syndrome:
- syndrome of compression of mediastinal structures;
- a specific symptom complex, characteristic of neoplasms of different localization;
- Nonspecific common manifestations of cancer.
The most common complaint of patients with signs of thymoma is a feeling of discomfort, and sometimes severe pain, caused by the germination of a tumor substrate in surrounding tissues that have nerve endings. Pain sensations most often do not have a clear localization and are prone to irradiation into the neck and upper limb on the side of the lesion. Malignant thymoma with signs of metastasis in bone tissue can be accompanied by rather intense pains in the bones.
In connection with the close anatomical location of the tumor with the structures of the vagosympathetic trunk, with its compression, characteristic symptoms develop in the form of development of unilateral ptosis of the upper eyelid, enlargement of the pupil with simultaneous enophthalmos, local changes in skin temperature and pronounced dermographism.
Compression compression of the nerve, innervating the larynx and vocal cords, provokes the patient's hoarseness, and the defeat of the diaphragmatic nerve is accompanied by a one-sided elevation of the dome of the diaphragm.
In the projection of the upper floor of the mediastinum, where usually thymoma is localized, there are a lot of structures and vessels, therefore, when pressure is exerted on the walls of large venous vessels, a symptom-complex of blood outflow from the venous collectors of the upper half of the trunk arises. The patient marks constant headaches of compressive and pulsating nature, dizziness , which is amplified by sharp movements, pastose of soft tissues of the head and neck.
In some situations, the patient is forced to seek medical advice about the difficulty of swallowing both solid and liquid foods that result from the massive growth of the tumor substrate of thymoma, which compresses the lumen of the esophagus.
Symptoms that are observed in all patients with tumorous neoplasms of one or another localization are: severe weakness and a sharp decrease in ability to work, a short-term fever that does not stop receiving antipyretics, a progressive weight loss. In the terminal stage of thymoma, the patient develops symptoms related to intoxication syndrome, namely: arrhythmias, arthralgia, infectious and inflammatory complications with localization in the skin integuments and joints.
In connection with the fact that the thymus belongs to the most important structures-regulators of immunity, the slightest changes in this gland lead to a decrease in the protective properties of the organism and an increase in the susceptibility to the occurrence of infectious diseases in severe form.
Despite all the variety of clinical manifestations characterizing the damage to the thymus, in most cases, their non-specificity does not allow us to establish a diagnosis at the initial stage of the disease, therefore, ray methods of diagnosis play an important role in this situation.
Stages of thymoma
In oncologic practice, the classification of thymoma is used to determine the necessary volume of therapeutic measures, and according to this division four main stages are distinguished.
The first (1) stage of thymoma is a tumor substrate from all directions enclosed in a dense capsule, and this volumetric neoplasm has small dimensions. Timoma in the early stages of development is successfully treated by the method of corticosteroid therapy and surgical benefits.
In a situation where the elements of the tumor substrate are determined in the surrounding fatty tissue and the pericapsular region, we should speak about the second (2) stage of thymoma. The only effective methods of therapy for neoplasm in the stage of detailed symptomatology are surgical resection and dosed radiotherapy.
The further course of the disease with the germination of tumor elements in the nearby structures of the superior anterior mediastinal region indicates the progression of thymoma to the third (3) stage of the disease. The main expedient way to treat this degree is surgical resection with a preliminary preparation of the patient by the course of chemotherapy.
The fourth (4) stage of thymoma is accompanied by the spread of cells of the tumor substrate with the current of lymph and blood, that is, distant metastases appear. Therapeutic measures in this case are limited to the course of chemoradiotherapy.
Among the diagnostic measures that allow to determine not only the presence of thymoma, but also indicate the size of the tumor, its structure and degree of malignancy, the most informative are the ray instrumental methods of investigation. In most cases, standard fluoroscopy can diagnose large neoplasm sizes, and small-sized tumors are visualized only when computed tomography is performed.
Treatment of thymoma
When determining the tactics of managing a patient and applying an appropriate method of therapy, the attending physician should be based on the general condition of the patient, the presence of contraindications to this or that method of therapy, the extent of the prevalence of the tumor process.
The most effective way to eliminate a tumor lesion is considered surgical, but positive results of treatment should be expected only in the early stages of thymoma. In this case, it is possible to completely remove the bulk tumor tumor, since it has clearly delineated boundaries. The surgical manual is performed through the median sternal access and, in addition to the radical removal of thymoma, it is recommended to perform a sectoral resection of the surrounding structures of the upper level of the mediastinum in order to prevent recurrence of tumor growth.
If there are signs of infiltrative growth of the tumor with damage to nearby organs, resection of thymoma is considered impractical. The tumor substrate allocated by operative access is necessarily subjected to a histological examination to determine signs of malignancy of the tumor process, and when confirming malignancy in the postoperative period, the patient is shown to undergo radiation or chemotherapy.
The early postoperative phase is dangerous because during this period the patient may have signs of a myasthenic crisis that need urgent measures (tracheotomy, long-term artificial ventilation, detoxification therapy).
Radiation methods with thymoma are used not only as diagnostic, but also therapeutic measures. To eliminate cancer cells, high-energy X-ray ionizing radiation is used. Radiation methods of therapy are used as a supplement to surgical treatment in the postoperative period and are more effective when combined with the use of chemotherapy drugs. It should be borne in mind that this method of treatment does not belong to the category of sparing for the health of the patient, and in some cases, its use may be accompanied by the development of adverse reactions in the form of violations of the digestive tract, rapid fatigue and skin reactions. In most cases, adverse reactions do not require the use of specific treatment and are self-leveling after the cessation of radiotherapy. The area of application of exclusively radiotherapy is considered to be cases of thymoma in the elderly category of patients, provided that there are contraindications to the operation.
As palliative medications for thymoma, drugs of the cholinesterase inhibitor group (1% Galantamine 1ml solution, 0.05% Prozerin solution 1 ml subcutaneously) are used.
In the overwhelming majority of cases of subcapsular thymoma, a combination of surgical and cytostatic therapy gives a 90% positive result, due to the use of the latest surgical minimally invasive technologies. Insufficiently studied, however, photodynamic therapy is considered a method of treatment with a pronounced positive effect on preventing the recurrence of the tumor process.