Destructive (cavernous) tuberculosis. Destructive tuberculosis Destruction of lung tissue in tuberculosis

Description:

Symptoms:

Causes:

By the beginning of the 90s, an unfavorable epidemic situation regarding tuberculosis had developed in the world. This applies to both developed and developing countries. Tuberculosis is recognized by WHO as a global problem causing enormous economic and biological damage. In 1993, the World Health Organization declared that tuberculosis was out of control and “in a critical situation worldwide.”

In Russia, this was due to the intervention of three powerful destabilizing factors in the epidemic process of tuberculosis: the socio-economic crisis, a decrease in the activity of anti-tuberculosis measures and the spread of HIV infection. In subsequent years, negative trends began to increase - preventive examinations decreased to 63-65% and against this background the proportion of destructive forms of tuberculosis increased.

According to R.Sh. Valieva (1987) among patients registered for newly diagnosed tuberculosis, destruction of lung tissue was found in 35.8%, bacterial excretion in 67.1%.

Over a ten-year period, the incidence of destructive forms of tuberculosis increased almost 2-2.5 times - from 12.3 per 100 thousand population in 1992 to 35.2 in 2004 and the incidence of bacterially excreted tuberculosis from 14.0 in 1992 to 35.2 per 100 thousand population in 2004.

The effectiveness of treatment of newly diagnosed patients according to the criterion of closing decay cavities in 1998 was 63.4%, according to the criterion of stopping bacterial excretion - 73.2%, which is 15% lower than the values in 1992.

The decrease in these indicators is due to a whole group of factors, both objective and subjective, ranging from a shortage of drugs to a change in the social composition of patients towards the predominance of unemployed people, their negative attitude towards treatment, an increase in the number of patients with acutely progressive forms of tuberculosis, caseous pneumonia with abundant bacterial excretion .

The initial massiveness of bacterial excretion creates serious difficulties in curing tuberculous changes, since it fully reflects the prevalence of pulmonary tuberculosis with multiple destructions and slow involution of a specific process. The insufficient effectiveness of treatment for patients with various forms of destructive pulmonary tuberculosis is directly related to impaired immunity due to various endogenous and exogenous factors and the lack of their positive dynamics during chemotherapy, as well as drug resistance of Mycobacterium tuberculosis (MBT).

On the problem of destructive pulmonary tuberculosis.

The epidemiological situation of tuberculosis in any region depends on the reservoir of tuberculosis infection circulating in the environment surrounding a person and environmental factors. The reservoir of infection is associated with the number of patients secreting tuberculous mycobacteria, i.e. sick, primarily with destructive forms of pulmonary tuberculosis. The possibility of reducing the reservoir of infection depends on the cure of such patients. Therefore, studying the epidemiology of destructive pulmonary tuberculosis, its clinical course depending on the immunological and psychological state of the body, drug resistance of Mycobacterium tuberculosis (MBT), as well as environmental and geochemical factors influencing them in modern socio-economic conditions and improving methods of its treatment seems relevant the task of phthisiology.

For the purpose of differentiated treatment, pulmonary tuberculosis, according to qualitative characteristics, has long been divided into small forms without decay, widespread without decay and destructive.

All destructive pulmonary tuberculosis with such a division of processes according to qualitative characteristics is assigned to one category and, accordingly, a uniform method of treatment is recommended. Meanwhile, destructive processes in the lungs are extremely heterogeneous. The existing literature does not provide criteria for distinguishing the described categories of processes, or the criteria are very heterogeneous and without appropriate justification; sometimes not so much the number and size of cavities are taken into account, but the prevalence of infiltrative and focal changes.

Thus, the question of dividing destructive pulmonary tuberculosis into groups according to qualitative and quantitative characteristics before the start of its study by the staff of our department was only at the stage of problem formulation. Meanwhile, this is important not only for differentiated treatment, but also for comparative assessment of the effectiveness of various complex therapy regimens proposed by different authors for implementation from the point of view of evidence-based medicine. However, a detailed analysis of the literature of that time did not allow us to evaluate them comparatively and identify the most effective among them.

Destruction of lung tissue is not just a complication of the disease, it is an indicator of a qualitatively different form of the tuberculosis process, the occurrence and course of which is apparently determined by primary immunodeficiency. The implementation of the latter in the disease of tuberculosis depends on various reasons, known as risk factors. Non-destructive forms of the disease, once established, rarely progress and are detected during preventive fluorographic examinations of the population. Destructive tuberculosis forms in a short time during the period between two fluorographic examinations, manifesting itself with symptoms. It is more often diagnosed in clinics when visiting a doctor. Among the destructive forms, there are variants that differ in the rate of progression. Therefore, the concepts of minor and initial (early) tuberculosis are not identical. The incidence rate of destructive pulmonary tuberculosis per 100,000 population, as well as the number of patients who died within a year after the onset of the disease, and the number of patients who became ill again with bacteriologically positive tuberculosis are the main ones for assessing the epidemiological situation of tuberculosis. The indicator of the general incidence of tuberculosis in the population should be regarded as additional, and not primary.

The analysis showed that the frequency of detection of destructive tuberculosis with a fluorographic examination once a year, for example, was in 1994. - 33.1%, gradually decreased and amounted to in 1998. - 32.2%. This suggests that even with regular annual examinations of the population, destructive tuberculosis is detected in every third case, i.e. This is not the neglect of the case, as was previously believed, but the uniqueness of the course of tuberculosis. When assessing the passage of fluorography among patients identified by referral, it was found that among those whose last fluorographic examination was less than 1 year, the frequency of detection of destructive tuberculosis was 41.1% -53.4%, which once again confirms the possibility of the formation of destruction in a short time period. At the same time, among those who were not examined for more than 5 years or did not undergo fluorographic examination, the frequency of destruction was 66.7% -73.8%. The results of our data formed the basis of regulatory documents for determining the frequency of preventive examinations for tuberculosis depending on risk factors and professional affiliation, approved by Decree of the Government of the Russian Federation No. 892 of December 25, 2001.

The conducted studies suggest that the use of the incidence rate of destructive pulmonary tuberculosis per 100 thousand population helped to objectify data on the epidemiological situation of tuberculosis both in the Republic of Tatarstan and Russia, because since 2005 it is included in the official statistics of the Ministry of Health and Social Development of the Russian Federation.

We tried to divide destructive pulmonary tuberculosis into groups based on the main feature - the timing of healing of decay cavities with conventional chemotherapy and some other treatment regimens. Then the remaining signs of the clinical course of the disease were assessed, which confirmed the existence of qualitative differences in the groups identified by the main sign (Table 1).

Table 1

Terms of closure of decay cavities as a percentage for various types of destructive pulmonary tuberculosis

In parentheses - intensive complex treatment

A detailed analysis of the treatment results made it possible to identify the following variants of destructive pulmonary tuberculosis, which clearly differed in terms of the timing of healing of decay cavities:

1. Pulmonary tuberculosis with minimal destruction (MDT). This includes cases where the decay phase was diagnosed by indirect signs (47 observations) and cases where there were decay cavities less than 2 cm (usually up to 1.5 cm), single (135 observations) or multiple (73 observations). The analysis showed that the timing of closure of decay cavities, including multiple ones, in all these cases, is approximately the same and differs sharply from the healing time of larger cavities. After only 2 months of treatment, the decay cavities were no longer detectable in a third of the patients, and after 4 months - in two thirds of the patients. In most cases, where the cavities were no longer detectable, at a later date it was possible to establish that in the areas of infiltration of the lung tissue there were caseous foci with their partial melting, on which the slow dynamics depended. Some of these patients developed typical tuberculomas during treatment.

2. Limited destructive pulmonary tuberculosis (LDT). Initially, we included here only processes with single decay cavities of medium size (2-4 cm). It turned out that cavities with a diameter of 2 cm occupy an intermediate position in terms of closure between cavities up to 1.5 cm and cavities 3-4 cm in size, which are closer to the latter in location. Therefore, we classified processes with such cavities as limited destructive pulmonary tuberculosis.

Further analysis showed that in cases where there are 2 cavities with a diameter of 2-4 cm or (rarely) a combination of one such cavity with one or more small cavities (up to 1.5 cm), the timing of closure with conventional chemotherapy is the same as for single cavities and differ sharply from the healing time of multiple (system) cavities of the same size. This forced us to combine both groups of processes into one category of limited destructive pulmonary tuberculosis. Closure of cavities in such diseases occurs 2-4 months later than in tuberculosis with minimal destruction.

3. Common destructive pulmonary tuberculosis (PDT). Based on the timing and frequency of cavity healing, we included in this group, firstly, processes with multiple decay cavities. In isolated cases there were 3 cavities, and most patients had a system of decay cavities, the number of which often could not be counted. Secondly, this category includes processes with large and giant caverns. In approximately half of these cases, such cavities were single; in the remaining patients, simultaneously with large cavities in the lungs, there were one or several medium-sized cavities (2-4 cm). Although healing of the latter was observed earlier, closure of large cavities occurred as late and rarely as in cases where they were single.

The table shows that the frequency and timing of cavities closure in widespread destructive pulmonary tuberculosis differs sharply from limited processes. And although these indicators in the presence of large cavities are significantly worse than in the case of multiple medium-sized cavities, we classified them into one category, because in both cases, equally intensive therapy is required. With conventional chemotherapy only after 8-12 months. the frequency of cavity closure reaches the same level as with limited destructive tuberculosis after 4 months.

The abrupt decrease in the effectiveness of treatment from group to group in terms of the frequency and timing of cavity closure in itself seems to be quite convincing evidence of the need to divide destructive pulmonary tuberculosis in infiltrative and disseminated processes into 3 distinct categories. They also differ in other indicators of the clinical course of the disease. In particular, the prevalence of infiltrative and focal changes in the lungs in most cases corresponded to the number and size of cavities. In cases of discrepancy, the timing of cavity closure depended more on their size than on infiltrative and focal changes. Therefore, we came to the conclusion that it is advisable to divide destructive processes into categories according to the main feature - the number and size of decay cavities.

This indicator usually corresponded to the severity of the intoxication syndrome and the timing of improvement in the condition of patients, as well as the massiveness of bacilli discharge and the timing of its cessation.

Due to the peculiarities of the dynamics of decay cavities and differences in treatment methods, when dividing newly diagnosed destructive pulmonary tuberculosis into categories based on qualitative characteristics, it becomes necessary to separate pulmonary tuberculomas with decay and fibrous-cavernous processes into separate groups.

4. We observed tuberculomas with decay in 75 patients. In less than half of the cases they were diagnosed immediately when patients were identified. In other observations, they were formed from infiltrative processes with decay during chemotherapy. The patients received a variety of treatments, but it was not possible to evaluate the effectiveness of individual regimens, because When divided into groups, each group contained a very small number of observations. The overall effectiveness of conservative therapy is presented in the table. It shows that the closure of decay cavities, sometimes as a result of their filling, occurs at a later stage.

5. We observed the fibrocavernous process in 32 newly diagnosed patients. Since cavities in this disease are very rarely identified, the results of treatment are not presented in Table 1.

The outcomes of pulmonary tuberculosis are another important indicator of the qualitative characteristics of destructive pulmonary tuberculosis. Observations of patients for 2 years or more showed that the final results depend on many factors: the age of the patients, concomitant diseases, chemotherapy tolerance, drug resistance of the pathogen, etc. But most of all, the outcome of the disease was influenced by its severity and prevalence, the method and duration of treatment in the hospital, and the discipline of patients regarding treatment at the outpatient stage. Under all circumstances, Table 1 shows clear differences in disease outcomes according to the identified categories of destructive pulmonary tuberculosis, which once again confirms the legitimacy of such a division and the reliability of the developed criteria.

Thus, it has been proven that destructive pulmonary tuberculosis in people who become ill for the first time, according to qualitative and quantitative characteristics, in order to develop differentiated treatment methods, it is advisable to divide into 5 categories. This made it possible to carry out differentiated treatment of patients, increase the effectiveness of treatment of severe forms of the disease, including caseous pneumonia, and reduce the drug burden of patients with relatively small tuberculosis processes in the lungs. The development of principles for differentiated treatment of patients depending on the qualitative and quantitative characteristics of the destructive process in the lungs is a new direction in the development of tuberculosis chemotherapy.

When testing new treatment methods in order to develop indications for them, and so that the results of studies by different authors are comparable, it is advisable to evaluate the effectiveness separately for each category of destructive pulmonary tuberculosis.

Based on long-term observation of patients with destructive pulmonary tuberculosis, new approaches to assessing the timeliness of their detection have been proposed.

Based on the comparative effectiveness of inpatient and outpatient treatment of patients with destructive pulmonary tuberculosis, we have shown that a significant part of them can be transferred to outpatient treatment or in a day hospital without waiting for the closure of the decay cavities, soon after the cessation of bacterial excretion and significant resorption of inflammatory changes in the lungs, which significantly reduces financial expenses.

R.Sh. Valiev

Honored Doctor of the Russian Federation, Honored Doctor of the Republic of Tatarstan,

Head of the Department of Phthisiology and Pulmonology KSMA,

Doctor of Medical Sciences, Professor

From the speech on April 22, 2009 at an extended meeting of the Academic Council of the Kazan State Medical Academy of Roszdrav
“IMPROVING METHODS OF DIAGNOSIS, TREATMENT AND PREVENTION OF PULMONARY TUBERCULOSIS IN CONDITIONS OF SOCIO-ECONOMIC TRANSFORMATIONS AND SPREAD OF HIV INFECTION”

Cavernous lung is a form of pulmonary tuberculosis in which cavities are found. It develops in cases where the progression of other forms (primary complex, focal, infiltrative, hematogenous disseminated tuberculosis) leads to the formation of a cavity, that is, a persistent cavity of decay of lung tissue. It proceeds without foci of dropout and without the development of perifocal inflammation.

In this disease, the cavity is a pathological cavity limited by a three-layer capsule, the inner layer of which consists of unrejected caseous masses, the middle layer is a layer of specific granulations, and the outer layer is a fibrous layer.

For cavernous tuberculosis, a typical symptom complex is the “decay phase syndrome”:

      * with the presence of sputum,
      * wheezing in the lungs,
      * hemoptysis,
      * bacterial excretion.

Number of observations

12 months and more

Minimal destructive tuberculosis

Limited destructive tuberculosis:
with one cavity 2-4 cm

with two caverns 2-4 cm.

Common destructive tuberculosis with a cavity system of 2-4 cm

with large caverns (5-11 cm)

In most cases, this form of the disease is a consequence of infiltrative tuberculosis. Initially, the infiltrate includes a focus of inflammation, in the center of which there are caseous masses (necrotic lung tissue), and in the perifocal infiltrate there are a large number of lymphocytes, leukocytes and macrophages. As a result of the death of these cells, a large number of proteases are released, which easily melt the caseosis. Liquid caseation begins to flow through the draining bronchus, and a decay cavity is formed. In this case, a diagnosis of infiltrative tuberculosis in the decay phase is made. During treatment, the perifocal infiltration around the decay zone begins to resolve and a cavity remains, near which there are always elements of productive inflammation, which are constantly transformed into caseous tissue. The cavity is formed during the resolution of perifocal inflammation and fibrosis.

Another variant of pathogenesis is transformation into a cavity.

The appearance of a cavity changes the characteristics of the tuberculosis process in an unfavorable direction. Conditions are created for the bronchogenic drift of infected sputum from the cavity through the draining bronchus into healthy parts of the lungs. Healing of the cavity is difficult due to the fact that the elastic traction of the lung or inflammatory compaction in its circumference interferes with the healing of the cavity and maintains the presence of air in it, which enters under pressure through the draining bronchus during deep breaths and coughing. The carrier of the cavity secretes tuberculous mycobacteria with sputum.

X-ray examination of cavernous tuberculosis reveals a round-shaped clearing with clear boundaries, located among focal tissues, in the center of the shadow of the infiltrate or within the capsule of the former tuberculoma, depending on what form of tuberculosis preceded the appearance of the cavern. Less often, the cavity is determined in isolation, in a clean pulmonary field, without the presence of other tuberculous changes in the lungs. This happens with complete chipping of tuberculoma caseosis from an isolated tuberculoma or with total disintegration of an isolated infiltrate.

CAVERNOUS PULMONARY TUBERCULOSIS

Cavernous pulmonary tuberculosis is characterized by the presence of a formed cavity, which appears as a visible shadow in the lung on an isolated ring on an x-ray. The existence of this form became possible only during the period of antibacterial therapy, when the existence of the tuberculosis cavity was not accompanied by contamination or pronounced infiltration. Cavern formation occurs with infiltrative or disseminated pulmonary tuberculosis.

Decay phase syndrome manifests itself as a cough with sputum, moist rales in the lungs, hemoptysis and bacterial excretion.

Formed cavern does not give pronounced symptoms. It is clearly visible on a longitudinal or computed tomogram. According to existing concepts, the cavernous form exists for up to 2 years, during which it is cured (including lung resection), progresses to fibrous-cavernous tuberculosis, or is complicated by fungal superinfection.

Cavity formations in the lungs may persist despite effective chemotherapy. These Cavities can become a source of pulmonary hemorrhage, especially if tuberculosis progresses.

The presence of terminal pulmonary arteries inside the caverns creates a risk of profuse pulmonary hemorrhage from so-called aneurysms Rasmussen.

Another cause of bleeding is the development of aspergilloma in a permanently existing tuberculous cavity (including sanitized cavities). In this case, bleeding is not associated with the progression of tuberculosis.

Breakthrough of the tuberculous cavity into the pleural cavity can also lead to tuberculous empyema and bronchopleural fistula.

Differential diagnosis

Syndrome ring-shaped shadows in the lung requires differential diagnosis with a lung abscess. An abscess is usually accompanied by an acute onset, high body temperature, chills, cough with copious purulent sputum, seeding of a virulent pathogen, and even hemoptysis. Negative tuberculin reactions, absence of M. tuberculosis in sputum, sharply increased ESR, pronounced leukocytosis. The abscess is more often localized in the lower sections and has a horizontal level of fluid in the cavity.

Lung cancer. Differential diagnosis should be carried out with disintegrating peripheral lung tumors. To do this, sputum is examined for atypical cells. Cancer is characterized by the presence of a wide zone of pericavitary infiltration due to tumor growth into the surrounding tissue. The internal contour of the cavity formed during the disintegration of the tumor is often uneven, characterized by a wide strand track to the root of the lung. Enlarged lymph nodes can be found at the root of the lung. The optimal method of radiological examination of a patient with cavity formations is CT, allowing a thorough examination of the condition of both the lungs and the mediastinum.

FIBROCAVERNOUS PULMONARY TUBERCULOSIS

The most unfavorable final in the progressive course of destruction, hyperchronic form - fibrous-cavernous pulmonary tuberculosis. It is characterized by thick-walled fibrous, often deformed cavities, gross fibrous changes in the lung tissue, deformation of the bronchi, displacement of mediastinal organs, constant or recurrent bacilli secretion of multiresistant strains M. tuberculosis, bronchogenic dropout centers, complications in the form of hemoptysis and pulmonary hemorrhage, amyloidosis with the development of uremia, irreversible LSN, spontaneous pneumothorax, intracavernous aspergillosis, etc. Patients with fibrous-cavernous pulmonary tuberculosis pose the greatest threat to the healthy population and require isolation and long-term chemotherapy. It is believed that in one cavity there are 10 10 -10 12 mycobacterium tuberculosis.

Flow

Fibrous-cavernous tuberculosis can be local and have quite stable flow. Often, chemotherapy can completely stabilize the process, and then sanitize the patient by removing the affected area of the lung. If the patient takes tuberculostatic drugs irregularly, abuses alcohol or eats poorly, progression of the process is inevitable.

Progressive type The course of this form of tuberculosis can occur from the very beginning of the disease; in this case, progression often continues despite chemotherapy, since multiresistance of mycobacteria to chemotherapy develops. The closure of the fibrous cavity with conservative therapy is unlikely. With a unilateral process, surgeons may suggest surgery, despite the activity of the process.

Forecast with this form of tuberculosis is often unfavorable. Progression inevitably leads to complications from which the patient gradually or suddenly dies.

in Russia from 1991 to 1996. the proportion of patients with fibrous-cavernous tuberculosis increased by 42.9%.

Differential diagnosis. The problem of differential diagnosis of fibrocavernous tuberculosis rarely arises. Bacterial excretion in combination with a typical x-ray picture eliminates many questions. In oligobacillary patients, there may be doubts about the diagnosis, then chronic abscess, congenital air cysts of the lung, bullous formations, limited accumulations of air in the pleural cavity with empyema are taken into account.

In polycystic disease, ring-shaped shadows are of the same type and multiple, there are no pleuropulmonary cords characteristic of cavities, and track to the root of the lung.

For bullae, a multiplicity of formations, angularity, scalloping, and discontinuity of contours due to the multi-chamber nature of these formations are more typical.

Any form of tuberculosis can be complicated by the melting of caseosis, the release of caseous masses through the bronchi and the formation of a cavity, i.e., the transition of the process to a destructive form. When caseosis melts along the edge of the tuberculosis focus, caseous masses can be separated according to the sequestration type. Such a cavity is called sequestering. When caseous masses melt according to the type of autolysis, the cavity has an autolytic character. The formed cavity is characterized by a three-layer structure of the walls: the internal caseous-necrotic layer faces the lumen of the cavity; behind it comes a layer of specific granulations containing epithelioid, lymphoid and Pirogov-Langhans giant cells; the outer fibrous layer borders the surrounding lung tissue and consists of connective tissue fibers infiltrated by lymphoid cells and containing more or less blood and lymphatic vessels. Caseous-necrotic masses and tuberculous granulations from the walls of the caverns pass to the walls of the draining bronchi. The intensity of inflammatory changes in the bronchi decreases as they move away from the lumen of the cavity, and in the area of the lobar and main bronchi only lymphoid infiltration into epithelioid giant cell tubercles in the submucosal layer is usually observed.

According to their genesis, cavities can be pneumonogenic, formed at the site of the focus of tuberculous pneumonia, bronchogenic, formed at the site of the bronchi affected by tuberculosis, hematogenous, arising from hematogenously disseminated tuberculosis. Depending on the structure of the walls and the severity of the fibrous layer, the cavities can be elastic, easily collapsing, with poorly developed fibrosis, and rigid with dense fibrous walls. By size, cavities are distinguished as small - with a diameter of up to 2 cm, medium - from 2 to 4 cm, large - from 4 to 6 cm and giant - more than 6 cm. When the cavities heal, the caseous-necritus layer is rejected, the lumen of the cavity decreases due to wrinkling of the walls, as well as the proliferation of granulations and fibrosis. Ultimately, a scar may form at the site of the cavity, in the center of which there is sometimes a small residual cavity lined with epithelium and containing clear fluid.

During the healing process of the cavity, the lumen of the draining bronchi may become obliterated; in this case, in place of the cavity, an encapsulated focus of caseosis such as tuberculoma is formed (see above). Under unfavorable conditions, caseosis in such a focus may again undergo melting with an opening; lumen of the bronchus and a cavity forms again, therefore this type. healing is incomplete.

When healing, rigid cavities most often transform into a cyst-like cavity. In these cases, rejection of the caseous-necrotic layer and replacement of the layer of specific granulations with nonspecific connective tissue is observed. The cavity turns into a cyst-like cavity. This process is lengthy, and areas of specific granulation tissue can remain in the walls of these types of cavities for a long time.

In the dynamics of the cavity during the development of healing processes in it, the state of blood and lymph circulation in its walls is of great importance. Even V.G. Shtefko (1938) emphasized the role of lymphatic drainage in removing decay products and cleansing the cavity. Much attention is currently paid to the processes of microcirculation in the wall of the cavity during its progression or healing.

A zone of perifocal inflammation often forms around the cavity, expressed with varying intensity. This zone represents areas of polymorphic pneumonia and lymphocytic infiltration. When the cavity is delimited and the pathological process is stabilized, especially with the use of specific anti-tuberculosis drugs, the pneumonic areas resolve. At the same time, fibrous changes increase in the form of strands of collagen fibers stretching from the fibrous layer of the cavity wall into the surrounding lung tissue. In such a cavity, a large number of lymphocytic accumulations and nodules are usually detected, up to the appearance of typical lymphoid follicles, located both between the connective tissue fibers of the capsule and especially at the border of the fibrous wall of the cavity and the surrounding lung tissue. These lymphocytic nodules and infiltrates are now, as already mentioned, considered to be manifestations of the body's immune reactions, which apparently play a large role in the healing processes.

The progression of destructive tuberculosis is expressed in an increase in the caseous-necrotic layer, which can pass to a layer of specific granulations and fibrosis. Perifocal inflammation is observed in the surrounding lung tissue, and foci of specific pneumonia are formed. Changes also progress in the bronchi with the appearance of foci of acute bronchogenic dissemination.

Cavernous pulmonary tuberculosis is characterized by the presence of an isolated formed cavity without pronounced fibrous changes in its walls and surrounding lung tissue. Most often, the cavity is located in one bronchopulmonary segment, directly under the pleura or in the deeper parts of the lung. The caseous-necrotic layer in its walls is thin. The main part of the wall is made up of a granulation layer, abundantly infiltrated with lymphoid cells; it contains well-represented vessels, often penetrating the entire thickness of the granulations and reaching the inner surface. A slight dissemination of the process along the bronchi is possible, limited, as a rule, to the affected segment (Fig. 13). Due to the absence of pronounced fibrosis in its walls, such a cavity can, under the influence of treatment, collapse and heal with a scar. If the cavity is located directly under the pleura, with which its outer wall fuses, healing can occur by cleansing the inner surface of the cavity and transforming it into a cyst-like cavity.

Fibrous-cavernous tuberculosis. Typical for this form is the presence in one (usually the right) or both lungs of a cavity or cavities located among fibrously changed lung tissue. In the walls of caverns, in contrast to cavernous tuberculosis, the fibrous layer is sharply expressed and prevails over caseous-necrotic and granulation layers (Fig. 14). The shape of the cavity is different. Multiple decay cavities can form a communicating system of cavities. The internal surface of cavities is usually uneven due to an unevenly expressed caseous-necrotic layer. Sometimes “beams” are found on it, which are the bases of obliterated blood vessels running through the “cavity.” Near the caverns there are usually acinar or lobular foci of bronchogenic dissemination, encapsulated or fresh, without a capsule. As the process progresses, an exudative-necrotic reaction predominates in the wall of the caverns and bronchogenic dissemination is expressed, which has an apico-caudal distribution, most intense in the middle and decreasing towards the lower parts of the lungs. A distinctive feature of bronchogenic disseminations of the present time is their clear demarcation from the surrounding tissue, preventing the process from transferring to the alveoli. However, even in modern conditions, the process can take on an acutely progressive character with the appearance of foci of a peculiar polymorphic pneumonia, caseosis of the bronchial walls, the formation of acute decay cavities with thin, poorly formed walls and a large perifocal reaction.

Fibrous-cavernous tuberculosis characterized by a wave-like course, and during the period of stabilization or subsidence of the process, the phenomena of fibrosis and deformation of the lung tissue increase. Fibrous-cavernous tuberculosis undergoes healing much worse than cavernous tuberculosis. Fibrosis prevents the circulation of blood and lymph in the walls of such cavities; with increasing fibrosis in tuberculous granulations, the macrophage reaction decreases, and fibrotic changes in the root of the lungs, pleura and surrounding lung tissue prevent the collapse and scarring of cavities. Therefore, only fibrous cavities of small sizes can heal with the development of a scar. Large fibrous cavities often heal by cleansing their walls and forming a cyst-like cavity.

Cirrhotic pulmonary tuberculosis characterized by the development in the lung tissue of severe, organ-deforming sclerosis (cirrhosis), bronchiectasis, post-cavernous cyst-type cavities, emphysematous bullae or caverns without signs of progression. Between scars, lesions of different sizes and structures can be identified. Cirrhotic changes in the lungs can be unilateral or bilateral, segmental, lobar, or occupying the entire lung. The cirrhotic lung is sharply deformed, reduced in volume, dense. The pleura is thickened, sometimes significantly, and covers the entire lung with a shell; ossification can occur in it. Due to massive fibrous cords, the airiness of the lung tissue is sharply reduced, areas of atelectasis alternate with areas of emphysema. The bronchial tree is sharply deformed, there are bronchiectasis of various sizes and shapes. A restructuring is observed in the blood vessels with recalibration of their lumen, the appearance of closing type vessels, and many gaping arteriovenous anastomoses (Fig. 15).

Among pronounced fibrosis, tuberculosis foci with variously expressed signs of process activity can be identified. They often form in the walls of ectatic bronchi or form in place of cavities during obliteration of the draining bronchi. In the walls of dilated bronchi, bronchiectatic cavities and cleared cavities, nonspecific inflammation is usually expressed. With significant sclerosis and the absence of active tuberculous changes in it, cirrhosis of the lung occurs as a consequence of tuberculosis.

Posttuberculous pneumosclerosis refers to residual changes after cured tuberculosis. Residual changes are characterized by the presence in organs previously affected by tuberculosis, scars of varying lengths, calcified lesions, and cystic cavities. Healing of tuberculous foci or cavities, no matter in which organ they are localized, leads to increased development of connective tissue, replacing tuberculous granulations. In this case, deformation of the affected organ is observed. When assessing scar changes in the lungs, it is necessary to distinguish between fibrosis, sclerosis and cirrhosis. Pneumofibrosis is a general concept of the development of connective tissue in the lung. Sclerosis refers to the development of collagen fibers, limited in extent, but not leading to greater deformation of the bronchi and lung tissue. Cirrhosis is understood as pronounced sclerotic changes with deformation of the bronchi and lung tissue, and a decrease in its size.