Enlarged thymus gland in infants: causes, symptoms, treatment

2024 Author: Priscilla Miln | [email protected]. Last modified: 2023-12-16 00:21

An enlarged thymus gland in an infant can cause disturbances in cellular immunity, reduce the body's ability to resist infections and cause autoimmune diseases. But pathology in most cases is not dangerous. This most important organ of the immune system grows until about the age of ten, especially active growth is observed in childhood. If an infant has an enlarged thymus gland, does this condition require treatment?

Functions of the thymus

The thymus gland, or thymus, determines the state of immunity. The gland is located in front of the sternum, ending at the root of the tongue. An organ is formed at the very beginning of intrauterine development of the fetus. The thymus is initially small but enlarges over time and stops growing at maturity. In adults, when immunity is alreadyformed, the gland atrophies as unnecessary. But until that time, it is important to monitor the condition of the thymus gland in order to prevent excessive enlargement.

The endocrine organ is necessary for the normal functioning of the body, but for a child of the first years of life, the thymus is especially important, because it protects the immune system that is not fully formed from various diseases. The thymus provides the synthesis of T-lymphocytes, which effectively fight pathogenic microorganisms, infectious and viral agents. The thymus is an important part of the immune system, in case of problems with which the body becomes susceptible to negative internal factors and environmental risks, and the general well-being of the child worsens.

Thymus size: normal

The size of the thymus is measured in units of CTI - this is the cardiothymic-thoracic index. To determine this indicator, in the process of ultrasound, the anterior-posterior size of the thymus and the width of the lobes are measured. Normally, the volume of the thymus gland in children under two years of age is up to 0.33% of body weight, in three to four months a maximum of 0.4% is reached. At the age of two to three years, the normal volume of the organ varies from 11 to 33 cm3. For an accurate assessment, the thymus mass and index are calculated (thymus mass ÷ child's body weight x 100%).

For newborns, the norm is TI ranging from 0.18 to 0.66%, at the age of one to three months - 0.24-0.73%, from four to six months - 0.13-0, 58%, from seven monthsup to a year - 0.13-0.57%. The relative weight of the thymus gland per kilogram of weight of a newborn child should be 4.2 g, at the age of one to five years - 2.2 g, the total weight of the thymus at the age from birth to one year - 13.26 g. There are summary tables of the ratio of the width, thickness and length of the lobes, which allow instrumental methods to diagnose an enlarged thymus gland in infants.

Possible pathologies

With an increase in the KTI indicators, an enlarged thymus gland is diagnosed in a child under one year old. This condition is characterized by the fact that the organ, under the influence of certain internal or external factors, changes its size, which negatively affects its functioning. In medical practice, the pathology is called thymomegaly. Hyper- or hypoplasia can be diagnosed: with hyperplasia of the thymus, tissues grow, a neoplasm is formed, and with hypoplasia, the function of T-lymphocytes is impaired. You can independently identify the presence of problems in a newborn, only focusing on indirect symptoms, and instrumental methods will allow you to accurately diagnose the pathology.

Symptoms of gland problems

If a child has an enlarged thymus gland, this condition is usually accompanied by symptoms of reduced immunity. Frequent colds and coughs are possible, which are not associated with the flu or SARS and are aggravated in a horizontal position, enlarged adenoids, lymph nodes or tonsils. Enlarged thymus syndromemanifested by such signs: heart rhythm disturbance, rapid weight gain or loss, pallor, frequent regurgitation, sweating, venous network on the chest, reduced muscle tone, cyanosis of the skin during crying and tension, overweight at birth, other developmental anomalies (syndactyly, hernia, hip dislocation).

Stages of change

In most cases, a slightly enlarged thymus gland in an infant does not require treatment, but the doctor will definitely determine the degree of pathology. This is necessary to make sure that the disease does not pose a threat, but for now it requires only observation. The borderline indices of the TI index for the first degree range from 0.33 to 0.37. The second degree is diagnosed with a CTI of 0.37-0.42, the third - over 0.42. Some doctors talk about the disease only with an increase in the CTI above 0.38.

To determine the severity of the pathology, the practitioner can use another method (diagnosis according to E. Dadambaev). To take into account the degree of enlargement of the thymus gland in infants, each half of the chest at the level of the third rib is conditionally divided into three equal parts vertically and horizontally. The increase is classified into noticeable (first degree) and significant (second degree). At the same time, the accuracy of diagnosis depends on the qualifications of the doctor and is assessed subjectively.

Causes for the development of pathology

Why is the thymus enlarged? It is quite difficult to reliably establish the cause of an increase in the thymus in an infant. The condition may be related tounfavorable heredity or a temporary violation that occurs due to imperfections and failures in the formation of the child's body. As a rule, the thymus returns to normal on its own, but subject to certain preventive measures. But if appropriate treatment is not available, and the degree of pathology is significant, then a number of autoimmune diseases can develop.

Why is the child's thymus enlarged? Among the factors that affect the increase in the size of the thymus can be listed:

• pathology of fetal development during mother's pregnancy;
• infectious diseases suffered by a woman (especially in the first trimester);
• complicated obstetric history (abortions, miscarriages, gynecological diseases in the past, primary miscarriage);
• use of certain drugs;
• complications of pregnancy: Rhesus conflict, late toxicosis;
• complications in childbirth (weak labor, asphyxia, birth trauma, jaundice, sepsis);
• various gene anomalies;
• preterm birth;
• late pregnancy.

Thymomegaly diagnosis

A pediatrician or narrow specialists, if an enlarged thymus gland in an infant is suspected, will study the mother's history and the course of pregnancy, the neonatal period and the child's anthropometric data (weight and height gain, birth indicators). Can confirm or refute the diagnosisonly instrumental and laboratory diagnostic methods: ultrasound, X-ray of the sternum, immunogram. Ultrasound and X-ray will allow to determine the size of the gland and calculate the CTI, and in blood tests in pathology there is a reduced concentration of T-lymphocytes, a limitation of the functional activity of these cells, a decrease in the number of immunoglobulins A and G.

Treatment for enlarged thymus

Slight enlargement of the thymus gland in infants does not require specific treatment. In the first and second stages of the pathology, it is necessary to ensure observation in dynamics and be attentive to the state of he alth of the child. It is necessary to establish breastfeeding, ensure sufficient physical activity, limit the contact of the baby with infectious patients. If breastfeeding is impossible for some reason, then mixtures with a high content of useful elements and vitamins should be chosen. So, the main recommendations are aimed at naturally strengthening the child's immunity.

Special medical treatment is needed when the thymus is greatly enlarged or there are complications. In case of severe pathology, the question of the expediency of surgical intervention is decided. In the period of preparation for surgery and in the presence of severe disorders caused by thymomegaly, glucocorticosteroids are prescribed. To correct the body's immune defenses, a course of natural stimulants and adaptogens is recommended. The treatment regimen is selected individually.

Complications and consequences

A significant increase in the thymus gland in an infant can trigger the development of severe allergic reactions and autoimmune diseases, endocrine disorders (diabetes, obesity, and so on). Children with an enlarged thymus have a significantly increased risk of sudden death syndrome. Common infectious diseases with thymomegaly can be complicated by an increase in lymph nodes, pain in the abdominal cavity, otitis media, and rhythm disturbances in the contraction of the heart muscle. Children with this diagnosis are more likely to have colds and infectious diseases.

Prognosis for enlarged thymus

Enlarged thymus gland in infants most often does not require specific treatment. This organ grows intensively in the first years of life, especially in response to vaccination or previous diseases. This is a natural process of developing immunity. Thus, if the thymus gland is slightly enlarged in an infant, this is a variant of the norm. After two years (if the situation does not normalize), we can already talk about pathology, but, as a rule, by the age of five or six, the thymus stops growing. In the future, dynamic observation is simply necessary. With a significant increase in the thymus, it is necessary to strictly adhere to the recommendations of doctors. In most cases, the prognosis is favorable.