Theme of lecture

  SECONDARY  FORMS OF TUBERCULOSIS

Disseminated tuberculosis

 In this form of tuberculosis, foci of specific inflammation are formed in the lungs with a size up to 1cm, single or multiple, 1-side or 2-side, localized in 1-2 segment.

Pathogenesis and pathanatomy. FLT belongs to secondary tuberculosis, meaning that it develops in long-time infected organisms the with presence of some infectious immunity and has features of limited organ injury(       

     Theories of secondary tuberculosis development:

        – exogenic super infection;

        – endogenic reactivation of remining foci of infection.

surrounded with a connective tissue capsule, sometimes with elements of calcination

         Focal tuberculosis is localized on apical parts or under clavicles. It is connected with limited mobility of apices, their insufficient aeration, weak vascularisation, slow lymph circulation, hypersenssensivity. There is also possible of MBT coming from tonsils of cervical lymph nodes

Clinics.  Clinical symptoms in FLT are weak or absent that are connected with small spreading of process. That’s why this clinic form is frequently revealed during prophylactic fluorography investigationsOnly in 30 % there are symptoms of intoxication or complaints connected with bronchopulmonary injuries. Intoxication is reflected with not constant subfever, more often at night, sweating, fast tiredness. Some patients have small cough, dry or with excretion of small quantity of sputum, chest pain. Haemophtysis is rare. Symptoms of intoxication are most often in fresh soft-focal tuberculosis, lung in fibrose-focal.

       Physical data in this tuberculosis form are small. Sometimes during palpation there is found reflector muscular tension above the injured region. Percussion and auscultative changes are not found. Small dullness of percussion sound may take place only at sclerotic changes in pleura. Breathing above injured area is not changed or rough with prolonged expiration. During formation of destruction after coughing are heard wet rhonchi     Large value for proving of foci’s tubercular nature has finding of MBT. That’s why there is needed multiple investigation of sputum or washing water from bronchi by methods of simple bacterioscopy or flotation. But even at such research bacterial excretion is found iot more than 5-10 % of sick.

    Reaction on Mantu’s test with 2 TU (tubercular units) in sick people with FLT is positive, but it isn’t much different from reaction in healthy infected people.

X-ray examination plays first role for diagnosis of FLT.      The main X-ray criteria of FLT diagnosis:

              – Presence of foci in the lungs (shadows up to 1 cm);

              – Spreading in 2 segments.

       In soft focal tuberculosis there are seen focal shadows of small intensity with not clear borders, they are often grouped, sometimes with linear shadows of lymphomatosis coming toward the root

Fibrouse-focal tuberculosis is characterized by foci of high intensity with clear borders, sometimes with inclusion of calcinations, with deformated pulmonary picture, fibrose lines.   

Differential diagnosis. Clinical symptoms of FLT may simulate:

       – flu;  – chronic sepsis;  – hyperthyreosis.

 But in all these diseases X-ray signs are absent

  Similar clinical and X-ray picture may be present at focal pneumonia that has low-revealed symptoms. When diagnostic of tuberculosis is firm, patient is prescribed with antibiotics of wide action spectrum, avoiding remedies of anti- tuberculosis action (streptomycin, kanamycin, rifampicin etc.). Clinical reconvalescense, elimination of focal shadows during 2-3 weeks proves diagnosis of pneumonia.

Infiltrative lung tuberculosis (ILT)

      ILT is a zone of specific inflammation mostly of exudative character, with size more than 1 cm, with ability to progressing and destruction.

    Pathogenesis and pathanatomy.. Infiltrate develops as a result of perifocal inflammation around fresh foci that appeared due to exogenic superreinfection or endogenic reactivation. Thus it may be continuation of soft-focal tuberculosis. Often the stage of development in the lungs of fresh foci stays not revealed, and sickness is revealed with formed infiltrate .Tuberculosis infiltrate may be a result of perifocal, inflammation around severed old foci formed at involution of lung tuberculosis. Fast development of infiltrate is a result of hyperergic reaction of lung tissue to a high quantity of virulent MBT that quickly reproduces.Clinic. The onset and clinical course of ILT depends on specialties of morphologic structure of infiltrate, spreading of perifocal inflammation, size of caseous necrosis.

    In most cases ILT is diagnosed when patient comes to doctor. In 21-40 % of cases it has severe or subsevere onset and simulates flu or pneumonia. Body temperature is increased to 38-39C, there develops general weakness, sometimes appear chest pain, cough with excretion of sputum, sometimes with blood inclusions. At severe onset of ILT that is sometimes diagnosed as flu or pneumonia, one must remember that after 10-14 days even without treatment or in incorrect treatment patient’s condition may become better, temperature decrease that is connected with destruction of infiltrate, coughing of caseuos masses and decrease of absorption of toxic destruction products and intoxication. It calms the patient and doctor, but pulmonary process progress and symptoms come back.

       At the subacute disease’s development (in 40 % of cases) patients complain of tiredness, decreased appetites, general weakness, sweating, subfebrile temperature coughing. Often patient don’t pay attention to these symptoms, connecting them with overtiredness, smoking. The beginning may be without any symptoms (inapercept) onset of ILT.      During examination of sick with ILT there are not often revealed any derivations from normal. Only in some cases there is noticeable decrease of body weight connected with disease, some decrease of chest. Palpation lets reveal tension of bronchial muscles on injured side, increased voice trembling above the infiltrate. Dullness of percussive sound may be noticed only at infiltrates with diameter of 4 cm from chest. Breathing above the infiltrate may be rough, with prolonged, expiration sometimes weakened (in bronchial obstruction). Small and sometimes moderate wet rhonchi are heard in destruction of infiltrate.

     Bronchoscopy reveals tuberculosis of bronchus in 4-5 % of sick with ILT.

X-ray examination.

    1. On X-ray there’s seen a shadow, with diameter more than 1 cm  that in tuberculosis has some specialties.

    2. Localization in 1, 2, 6 segments (on anterior lower X-ray-above, under the clavicle and parahillary).

    3. Non-homogenic structure due to more intensitive foci conditioned by old fibrosis formations around which infiltrate developed or by caseoua foci. Areas of lighting also condition non-homogenic of infiltrate during formation of destruction cavities.

    4. Focal shadows with unclear borders around the inlitrate and in other parts of this or that lung as a result of lympha– or bronchogenoc dissemination;

    5. “Road” to the root often as double stripe of infiltrated walls of bronchus is revealed often at tuberculosis infiltrate in destruction phase

Besides these general signs of LIT, by character of X-ray changes and partially in connection with specialties of clinical picture and course of disease, they define some clinic-X-ray variants of ILT.

 1. Lobular infiltrate has a look of conglomerate of foci with  shadow of  perifocal inflammation.

 2.  Round shaped infiltrate – it is relatively homogeneous  shadow of round shape with more clear borders; during tomographic investigation there’s sometimes revealed destruction as area of lightening

 3. Lobitis: massive infiltrative shadow usually not homogenic. It develops in the whole lobe usually in upper right. It usually destructs, has clear lower borders

4. Periscisuritis – it is an infiltrate situated in lung tissue along the interlobular sulcus. It has clear borders, but the upper border is not.

 5. Cloudlike infiltrate is represented by multifocal low intensive shadow of irregular shape, with as a result of connection of several lobular infiltrates. It has high possibility to destruct).

  Caseous pneumonia is a clinical form of tuberculosos with massive caseous changes in lungs and severe, progressive clinical course.

Pathogenesis and pathanatomy. This process appears as a secondaryone in patients with decreased immune reactivity as a result after superreinfection by massive doses of highly virulent, sometimes resistant mycobactreria of tuberculosis or as a result after endogenic reactivation of old process with immunodepressive therapy. It is thought that some role for malignant course of disease plays secondary non-specific infection. Lobar caseous pneumonia develops on a background of cloud-like infiltrate or lobitis, when during expressed hyperergic tissue reaction becomes an almost total caseous necrosis of tubercular infiltrate, which dominates under the perifocal inflammation. Colicvation causes multiple cavities of disintegration of gigantic caverna, which occupies whole lobe of lung. Then infection in lungs can enlarge through bronchi

    Thus they’re the following variants of caseous pnemonia:

1. Lobar is a total caseous necrosis of cloudlike infiltrate or lobitis.

2. Lobuluar:

    –  As a result of aspirative pnemonia after bleeding;

    – Malignant course of subacute disseminative tuberculosis of

       lung;

    – Complications of terminal stages of chronic form of

       tuberculosis;

    – Spreading of caseous masses in bronchi and lungs through the

       fistula with lymphatic nodes.

Clinic. Disease begins acute, with high temperature of body and rapid increasing of symptoms of toxication, profuse sweat and at first suggests simply pneumonia. Patients complain of pain in chest, dyspnea, cough with excreting of green sputum. The face is pale with cyanosis of lips, expressed tachycardia. There is a percussive dullness under the injured areas, bronchial breathing, loud “caseous” wet ronchi. The course of disease is rapid, progressive. Without adequate treatment condition of patients become worse, in several weeks death comes because of expressed intoxication, heart-breathing insufficiency. Sometime the process complicates with a bleeding.

Laboratory and other instrumental investigations. There is a hypochromic anemia, leukocytosis 12,0-20,0*109/l, eozynopenia, lymphopenia, SES increasing till 50-70 mm/h. after the toxic injuring of kidneys in urine appear erythrocytes, leukocytes, protein, cylinders. There are signs of toxic myocarditis on the ECG. When the excreting of caseous masses appears, mycobacteria tuberculosis can be found. Reaction to tuberculin can be weak positive or even absent during expressed allergy.

     X-ray investigation determines massive uneven darkness of entire lung lobe during caseuos pneumonia, there can be separate intensive processes on the background of it. While next progressing of process shadow becomes almost homogenic, than on its background lightening of cavity destruction appears or gigantic caverns form. Lower lobar shadow in other regions of either lung’s broncho-dissemination processes appear.

During lobar caseous pneumonia big processes with irregular margins are defined (if lobular caseous pneumonia appears on the background of disseminative tuberculosis, they are localized symmetrically in both lungs). During the progressing of disease in pneumonic foci appears multiple lightening of cavity destruction, in other lungs there are new bronchogenic injured places, which are united rapidly and destruct.

. Differentiated diagnosis of lobar caseous pneumonia should be made with simple (croup) pneumonia, which is also develops acute, but sometimes begins with rhinitis, herpes; those are not specific signs for caseous pneumonia. Body temperature during croup pneumonia is persistent, while during caseous pneumonia it is irregular with remissions. For caseous pneumonia profuse night sweat is usual, while during croup pneumonia it appears during crisis. More expressed leukocytosis (20-40*1012/l) can be during croup pneumonia.

X-ray signs of croup pneumonia are the following:

           Homogeny shadow limited in a lobe.

  X-ray signs of caseous pneumonia (fig.10):

         1. Uneven shadow, that can be spread;

         2. Appearing of lightening because of emptiness destruction;

         3. Injured places of bronchogenic dissemination in other

             places in the same lung or another lung.

        For full determination of tubercular origin of disease multiple searching of mycobacterium tuberculosis in sputum is necessary. Diagnosis of lobular pneumonia, which develops as a complication of other forms lung tbc is difficult.

 

Fibrous-cavernous lung tuberculosis

 

Pathogeny and signs of cavity.

 

         The destructive changes can appear at any form of lung tuberculosis. They are found in 30 – 35% first exposed patients approximately, more frequent all at progress of infiltrative and disseminated lung tuberculosis, rarely – focal. Consider that formation of caseous necrosis is investigation of hyperergic inflammation, in which the systems accountable for the machineries of the promoted sensitiveness of slow type take part.

   Stages which are passed by a destructive process in lungs 

·  fresh disintegration;        ·  elastic cavity ·  fibrous cavity

 On a roentgenogram or tomogram fresh disintegration has the appearance of light of wrong form on a background infiltrative darkening. The internal contours of cavity are unclear, external – meet with shade of infiltrative. The wall of her consists of 2th layers: cazeous-necrotic and narrow layer of specific granulation.
   Gradually there is the subsequent tearing away of cazeous, his from a border of granulation. With appearance in the wall of the third, external connective layer, a cavity is considered a cavity. This layer is irregular at first, thin (elastic cavity). On a roentgenogram an elastic cavity has the appearance of correct ring-shaped shadow with thin walls, clear internal and some washed out external contour..
         Consequently, lines belong to the basic roentgenologic signs of cavity of disintegration direct:·  ring-shaped shadow integrity of which is saved in different projections;  indirect : ·  horisontal level of liquid;  ·  double bar of drainage bronchi;        ·  bronchogenic metastases.

 On a roentgenogram of fibrous cavity has thick walls, clear internal and external contours. At the expressed sclerotic changes round a cavity, she becomes deformed, becomes oval, poligonal. Such cavities are heavily added to the conservative methods of medical treatment

      Consequently, possible ways of cicatrization of cavities with education     ·  scar;        ·  hearths;        ·  blocked cavity;        ·  pseudocysts.

Fibrous-cavernous lung tuberculosis.

This form is the result of unfavorable motion of destructive tubercular process. Basic its signs:  ·  old fibrous cavity; ·  fibrous in adjoining pulmonary fabric; ·  bronchogenic dissemination; ·  protracted motion with the periods of sharpening and remission; ·  periodic or permanent bacterioexcretion.

   Consequently, this form of lung tuberculosis epidemiology is dangerous.

         .Pathogeny and pathological anatomy. Fibrous-cavernous lung tuberculosis develops at unfavorable motion of infiltrative, disseminated and focal tuberculosis
 An old fibrous cavity which is localized mainly in the overhead departments of lung is the most important his sign. The wall of her has the three-layered structure.. An external fibrous layer prevails above other. Fibrous changes round a cavity are the second important sign of fibrous-cavernous lung tuberculosis.
       The third feature of fibrous-cavernous lung tuberculosis is this distribution of mycobacterium from a cavity on lymphatic vessels and bronchial tubes. Hereupoear the cavity, and also in the remote departments of the same or other lung are formed acinous, acinous-nodous and lobular hearths. They can meet, forming so called “daughter’s infiltrative” at cazeous disintegration of which new “daughter’s cavities” are formed. Thus there can be a polycavernous lung tuberculosis.
         The clinic of fibrous-cavernous lung tuberculosis relies on prevalence of process,phase of his development and complications.
         At fibrous-cavernous lung tuberculosis patients grumble about a cough: from the insignificant coughing to unrestrained one, which violates sleep of patient, that is the sign of tubercular defeat of bronсhi. Sputum of mucus-festering character, without an unpleasant smell incident to the unspecific pyogenic processes, clears one’s throat heavily. Pain in breasts relies on the defeat of pleura, not permanent, increases at a cough, but he is felt by not all patients. At considerable distribution of process, massive fibrous changes the shortness of breath develops.
       In a period sharpening of process the temperature of body rises (subfebrile  or febrile).

       Above the areas of fibrous, by the thickened pleura or areas of infiltration a percussion sound was dulled. Breathing above the massive cirrhotic changes, especially overhead part, bronchial not or is weakened, depending on permeability of bronchial tubes. Above a large smoothwall cavity the amphoric breathing can be listened. However more frequent above a cavity which was surrounded by the area of fibrous and infiltration or pleura stratifications, breathing was loosened. Above a cavity with liquid maintenance mid- or macrovesiculous moist wheezes are listened, at stiff consistency of maintenance to hear wheezes only during a cough on exhalation (expiration). At cleaning of cavity, reduction of its liquid maintenance, wheezes disappear. Above an old rigid cavity at times it is possible to hear out sounds which remind a “squeak” or “creak”.

A few variants of motion of fibrozno-cavernoznogo lung tuberculosis are distinguished:

·  limited fibrous-cavernous lung tuberculosis with stable motion;  

·  motion making to progress;       

· with complications.
         At the limited fibrous-cavernous lung tuberculosis with stable motion the process of relatively small slowness with a stable old cavity, by the surrounded area of fibrous The periods of remission are protracted – from a few months of to years. Selffilling of patients is satisfactory, a capacity is long saved. Bacterioexcretion сan not come to light in current protracted time. The such sick live 10- 20 years, at times die from the accompanying diseases.

         The type of motion of fibrous-cavernous lung tuberculosis making to progress at times takes place from the beginning of his forming. More frequent he acquires such motion in patients which violate the mode of medical treatment, practice upon swizzles. The value of the genetically conditioned features of the immune system caot be eliminated. Sharpening of process are frequent, the symptoms of intoxication were expressed sharply, are saved even in a period remission. There are broncho-pulmonary symptoms – cough, selection of sputum, pain in breasts, shortness of breath, at times haemorrages. Development of perifocal inflammation answers these clinical displays, bronchogenic dissemination, origin of new cavities of disintegration. Plural, sometimes giant cavities are formed. Motion making to progress can end by development of cazeous pneumonia, miliarisation. At such sick mycobacterium are selected, often firm to untituberculosis preparations, medical treatment not enough is effective.

Fibrous-cavernous lung tuberculosis with complications which it is possible to divide into unspecific and specific.

      Unspecific:

·  chronic pulmonary heart;·  amiloidosis of internal organs;·  haemorrages, bleeding;·  spontaneous pneumotorax;·  unspecific inflammatory processes;·  candidomicosis, aspergillosis.

      Specific:

·  tuberculosis of bronchi;·  bronchogenic dissemination (hearths, “daughter’s infiltrative” and cavities);·  tuberculosis of larynx;·tuberculosis of bowels.

      Roentgenologic research. Basic his signs are the presence of the thick-walled, sometimes deformed ring-shpape shadows with clear internal contours, surrounded by fibrous cords, and at sharpening of process – area of the infiltrative darkening. Roots are deformed. Intercostal intervals were narrowed. The organs of mediastinum can be displaced in the side of defeat. Below, in the same or other lung, it is visible focal or infiltrative shadows, that arose up as a result of bronchiogenic dissemination

.Differential diagnosis at the destructive forms of lung tuberculosis.

   The cavities of disintegration in lungs  are at the isolated air cysts or lung policistosis, chronic abscess, cavernous form of cancer, bronchiectasis illness and row of other diseases .  Researches which it is necessary to carry out at the exposure in lung of suspected on tuberculosis cavities of disintegration:     

·  frequent bacterioscopyc and bacteriological investigation of sputum; ·  cytological research of sputum;        ·  tomography;        · bronchoscopy with taking of material for cytologmical and histological analyses;   ·  punction or biopsy    

MILIARY   TUBERCULOSIS

     Miliary tuberculosis de­fines the presence of innumerable, tiny, discrete tuberculous lesions in the lungs and other organs owing to the seeding of these tissues by blood-borne tubercle bacilli.

  Miliary tuberculosis results from a massive hematogenous spread of tubercle bacilli, which may occur either at the time of primary infection or at a time remote from the primary infection. The quantity of the tuberculous bacillemia and the immunologic competence of the host are im­portant factors that determine the outcome of such dissemination.   A case­ous focus more easily may erode into a blood vessel, leading to widespread dissemination of the tubercle bacilli

   .The clinical presentation of miliary tuberculosis may vary significantly. Common symptoms include fever, weakness, anorexia, weight loss, and cough. Fever may be continuous but is often low-grade and intermittent.

    Anemia occurs in up to two thirds of patients. Leukopenia is less common but more frequent than leukocytosis. Mo-nocytosis and an elevated sedimentation rate are common. Rarely, disseminated tuberculosis may lead to pancytopenia, aplastic anemia, or a leukemoid reaction that may easily be confused with acute leukemia.

             A negative tuberculin reaction does not ex­clude the diagnosis of miliary tuberculosis, and a  positive PPD reaction only signifies that miliary tuberculosis is a possibility.The chest radiograph is the single most important means for detecting miliary tuberculosis.  At first the tiny nodules may have faint, hazy outlines, but they sharpen as they grow larger. Often they appear more numerous at the central and basal areas of the film because of the greater thickness of the lung at these sites. The nodules are usually most apparent where the lung shadow is superimposed over a radiodense structure such as the heart or diaphragm.

      The size of the nodules visualized in the initial chest film varies with their age. When symptoms or other clinical evidence raises suspicion of miliary tuberculosis, it is important to realize that a normal-appearing chest film, especially early in the illness, does not exclude this diagnosis. In this circumstance, repeated chest x-ray studies should be obtained every few days in order to detect lesions when they appear. It is also useful to examine the chest film before a bright light, which provides better visualization of the tiny nodules, especially in overpenetrated dark films