Disseminated tuberculosis. Lecture № 6. The Department of Tuberculosis of KSMA. Doc. Fydorova S.V.

Disseminated tuberculosis is usually consequence of lymphohematogenous spreading of TB-infection. May affect as children as adults, may be as single form of TB, as complication of other clinical forms.

Classification of disseminated TB By clinics: Miliary TB or acute disseminated TB: pulmonary form typhoidal form meningitic form acute tuberculous sepsis. Subacute disseminated TB. Chronic disseminated TB.

Classification of disseminated TB The second part – pathogenesis of disseminated TB: primary TB secondary TB

Classification of disseminated TB By the way of MBT-spreading: hematogenous lymphogenous bronchogenous mixed spreading (lymphohematogenous, lymphobronchogenous etc).

Classification of disseminated TB By volume of affected lung tissue: limited process wide-spreaded process

Pathogenesis and pathomorphology of subacute disseminated TB The source of lymphohematogenous spreading of TB-infection is usually affected lymph node. MBT enter into bloodstream, they are carried into the lung tissue and cause formation of focal specific lesions.

Pathogenesis and pathomorphology of subacute disseminated TB Exudative and alterative inflammatory reactions predominate, so focal legions can fuse together and cavities in the lung tissue form. Pleura, kidneys, bones, joints, gastrointestinal tract and other organs may be involved too.

Subacute disseminated TB Case of generalized subacute disseminated tuberculosis, autopsy. Involvement intrathoracic lymph nodes.

Subacute disseminated TB Case of generalized subacute disseminated tuberculosis, autopsy. Tuberculous cavities in upper lobe of lung.

Subacute disseminated TB Case of generalized subacute disseminated tuberculosis, autopsy. Involvement of kidneys.

Subacute disseminated TB Case of generalized subacute disseminated tuberculosis, autopsy. Involvement of mesenterial lymph nodes.

Subacute disseminated TB Case of generalized subacute disseminated tuberculosis, autopsy. Involvement of intestine (caseous, hemorrhages, fistulas).

Pathogenesis and pathomorphology of chronic disseminated TB In patients with chronic disseminated TB the spreading of infections is indulative. When the wave of lymphohematogenous spreading occurs, new focal tuberculous legions in the lung tissue appear.

Pathogenesis and pathomorphology of chronic disseminated TB All focal lesions are different from each other, because they are at different stages of their development: oldest of them are calcified, some of them are dens, and new fresh foci usually have area of perifocal exudative inflammatory reaction. There are TB cavities in the lung tissue. Fibrosis, sclerosis of the lung tissue is getting much expressed year by year.

Clinical forms of subacute disseminated TB are numerous and varied. They cane simulate a lot of different diseases: acute and chronic bronchitis, pneumonia, exudative pleurisy, acute respiratory viral diseases, infectious diseases (typhus, paratyphus) etc.

Clinical forms of subacute disseminated TB Different organs other than lungs can be involved in pathological process too, because lymphogematogenous spreading of infection takes place. In this cases TB process may simulate some spinal diseases (cervical or lumbal spondilosys, radiculitis, prolapsed intervertebral disk etcю), renal and urinary tract diseases (nephritis, tumors, urinary stones etc), peripheral lymphadenophathy (sarcoidosis, lymphogranulomatosis, lymphoma etc). Differential diagnosis may be difficult.

Clinical picture of chronic disseminated TB The main complaint in patients with chronic disseminated TB is breathlessness. It is getting stronger year by year. Other pulmonary complaints (cough, sputum production, chest pain) don’t express strongly. The disease has indulative pathway. Increasing of temperature, loss of weight and appetite, weakness usually take place during the exacerbation of disease. There are dysfunctions of endocrine and nervous system in some patients with chronic disseminated TB.

Diagnosis of disseminated TB Sputum microscopy with Ziehl-Nilsen staining is usually positive in patients with subacute disseminated TB. In patients with chronic disseminated TB MBT are usually detected by culture. PCR is expensive, but very sensitive and specific test.

Diagnosis of disseminated TB Tuberculin Mantoux test is informative in children, but it doesn’t give a lot of information in adult persons.

X-ray diagnosis of subacute disseminated TB Focal shadows are detected, they are usually located in the both lungs. The are often heterogeneous, they have different sizes, they can fuse together, but all of them have the same intensity. TB (stamp-like) cavities with a thin wall are often detected in upper parts. Sometimes accumulation of fluid in pleural cavity may be.

X-ray diagnosis of chronic disseminated TB There are polymorphic focal shadows in chronic disseminated TB. All foci are in the different stages of their development, so they are different from each other. Calcified foci have clear outlines, very high intensity. Fresh foci have unclear borders, because there is area of perifocal inflammation around them. There are cavities and sings of fibrosis: loss of volume of affected lobes, deformation of lung roots, formation of pleural lesions, dislocation of mediastinum etc.

Differential diagnose pulmonary disseminated carcinoma nontuberculous granulomatoses (sarcoidosis, lymphogranulomatosis, alveolitis etc.) professional diseases diseases of connective tissue etc.

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