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Primary tuberculosis complex in the lungs
Last reviewed: 23.04.2024
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The primary tuberculosis complex in the lungs is a characteristic triad consisting of a focus of specific inflammation at the site of the introduction of MW, lymphangitis and regional lymph node involvement. Currently, it is recognized that the classical primary tuberculosis complex with a pronounced pulmonary component, a large perifocal reaction develops in cases when such unfavorable circumstances are combined, such as massiveness, virulence of tuberculosis infection and a decrease in the immunobiological capabilities of the macroorganism. From the primary affect, a specific process spreads through the lymphatic ducts to the intrathoracic lymph nodes.
At alimentary penetration of the causative agent both human and bovine type primary affect can be localized in the intestine. Localization of primary affect in the skin, mucous membrane of the nose and middle ear, tonsils is casuistry.
With aerogenic infection, the primary tuberculosis complex most often develops in the lung tissue, according to A.I. Strukov, - in 95% of cases. In this case, peripheral (subpleural) departments are more often affected - mostly well aerated segments (usually segments II and III of the right lung). Initially, several alveoli are involved in the process - alveolitis is formed, in the future - bronchioles, bronchiolitis occurs. Thus, the primary affect is always always pneumonia. The magnitude of the pneumonial focus depends on the number of alveoli involved in the process: with a small amount, the pneumonia focus can have the size of millet grain, in other cases pneumonia can be acinous, lobular and even lobar.
In the early stages of development, the primary alveolitis does not have specific features, but the early non-specific phase is very quickly replaced by a specific phase with the development of curdled necrosis. The fresh focus of primary tuberculosis pneumonia is surrounded by a zone of perifocal inflammation due to toxic edema of the lung tissue. In the process, the pleura always participates, fibrin appears on its surface, in the subsequent it is organized.
At a time when MW begins to spread through the lymph nodes, the primary affect already reduces perifocal inflammation, the productive type of tissue reaction begins to prevail.
With the penetration of a specific process into regional lymph nodes, nonspecific inflammation first develops. After the exudative phase, necrosis develops very quickly, bypassing the development of tubercular granulations. In some cases, this early necrosis can cover the entire lymph node. Since tuberculosis is characterized by a wavy course, the primary complex morphologically is usually multilayered: exudative changes, necrosis is replaced by a shaft of granulations, then exudation, necrosis, etc. Reappear. The reverse development of the primary tuberculosis complex consists in the disappearance of the zone of perifocal inflammation, the replacement of the exudative reaction of the productive, the development of encapsulation. The primary focus is well delimited from the surrounding pulmonary tissue by a thick fibrous capsule, calcium salts are deposited in it, and in some cases bone formation forms during the involution of the process. In the lymph nodes, the processes of reverse development proceed much more slowly, but over time and in them come the hyalinosis of the capsule and calcination.
The primary complex can develop in different age groups, most often in younger children. Taking into account the fact that at the present time, along with a decrease in the children's infection, it shifts towards older age groups, the primary tuberculosis complex is also detected in adolescents.
Symptoms of the primary tuberculosis complex
Symptoms of the primary tuberculosis complex are diverse and depend on the severity of morphological changes at the time of the child's examination. Clinical symptomatology depends on the size of the caseous focus, mainly on the severity of the zone of trifocal inflammation in the specific process of the intrathoracic lymph nodes.
Inflammatory changes in primary tuberculosis depend to some extent on the child's age. Particularly pronounced propensity to extensive processes in the primary period in children in the age group up to 7 years. This circumstance is due to the fact that at this age the differentiation of the pulmonary tissue has not yet been completed, wide lumens of lymphatic fissures, friable connective septums, rich in lymphatic vessels remain, which promotes the spread of inflammatory changes. Clinical manifestations of the primary tuberculosis complex in children in the younger age group are expressed to the greatest extent and are characterized by widespread and complicated forms.
Symptoms of the primary tuberculosis complex
Diagnosis of primary tuberculosis complex
X-ray diagnosis of the primary tuberculosis complex is based on the identification of its main components: primary tubercular pneumonia, changes in the intrathoracic lymph nodes (often regional) and the so-called pathway that connects them. The variability of local manifestations is due to the different length of the primary pulmonary focus, its pathomorphological substrate (the ratio of caseous-exudative changes in the tissue response), the prevalence and character of the process in the hilar lymph nodes, and possible complications.
Radiographically, the shadow of primary tuberculosis pneumonia in the period of the active phase of the process is uniform, its contours are blurred, it is associated with a pathologically altered root "path" in the form of fuzzy outlined linear formations. Their morphological substrate is inflammatory transformation of lymphatic and interstitial tissue along the course of bronchi, vessels and lobules of the lung. The intensity of the shadow of the primary focus is different, which is due not only to its magnitude, but also to the severity of caseous necrosis. Changes in the intrathoracic lymph nodes are more often regional. In this case, roentgenologically determine the volume increase or expansion of the lung root, the violation of the differentiation of its structural elements, on the borderline in the affected area, blurriness, blurriness of the root contours is possible.
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