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Clinical syndromes of thymus (thymus)
Last reviewed: 23.04.2024
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The clinical equivalent of wasting syndrome can be considered manifestations of congenital aplasia of the thymus. This is a fairly rare disease, characterized by lymphopenia and agammaglobulinemia. Usually it appears after a three-month-old age of severe diarrhea, which is not amenable to treatment. Develop cachexia, persistent cough, stiff neck, and similar to measles rash. Serum completely lacks specific antibodies and isoagglutinins. The prognosis is extremely unfavorable, although there are data on the positive effects of thymus extracts. At the autopsy, an underdeveloped thymus is found that does not contain the body of Hassal, but is rich in mast cells. The entire lymphoid tissue is hypotrophic and is represented almost exclusively by the reticular cells without lymphocytes and plasma cells.
An example of syndromes associated with hypertrophy of the thymus gland is hemolytic anemia of the autoimmune nature, as well as the already mentioned malignant myasthenia gravis. In 15% of patients, this disease reveals true thymomas, and in 60-70% - hypertrophy of the thymus medulla containing embryonic centers. Plasmatic cells are present in the perivascular connective tissue of the thymus gland. The idea of the autoimmune nature is confirmed by the frequent combination of the disease with other autoimmune processes (disseminated lupus erythematosus), as well as the presence of antibodies to other tissues (thyroid gland), rheumatoid factor in the serum, etc. The serum of the patients contains specific antibodies not only to acetylcholine receptors muscles, but also to intracellular muscle antigens. Removal of the thymus in the early period after the onset of the disease often leads to a cure.
Morphological changes in the thymus (the appearance of germinal centers and plasma cells in it) are observed in other autoimmune diseases.
Tumor tumors are rare (5-10% of all mediastinal tumors). For the most part, they are epithelial or lymphoepithelial thymomas containing characteristic light cells. Sometimes these tumors are accompanied by a violation of the synthesis of serum globulins (hypo- or hypergammaglobulinemia) and various anemias (pancytopenia, erythropenia, thrombopenia, etc.). The relationship between small cell epithelial thymomas and the appearance of Cushing's syndrome is described. Removal of the thymus in such cases (especially in the presence of hematologic changes) has a positive effect. Thymus tumors can be malignant, germinating into surrounding tissues and metastasizing into the organs of the thorax. Lymphoepithelial thymomas are found in cases of granulomatous myocarditis and myositis. There are data (mostly experimental) on the role of thymus pathology in the genesis of lymphocytic leukemia.
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