PULMONARY TUBERCULOSISPULMONARY TUBERCULOSIS

Lung is a favorable site for T.B. (easy inhalation and aeration).

* Predisposing Factors:•Decrease immunity.•Silicosis.•Congenital heart diseases.

1ry pulmonary T.B1ry pulmonary T.B

* Age:• Children.* Mode of infection:• Droplet infection.* Lesions:• 1ry pulomnary complex (Ghon’s triad).

Primary pulmonary complex (Ghon’s triad)

Consists of 3 parts:

1. Parenchymatous lesion (Ghon’s focus):

- Tubercles which develop at the lower parts of

upper lung lobes or upper parts of lower lung

lobes, subpleural.

- Consists of caseating and caseating tubercles.

1. Tuberculous lymphangitis.

2. Tuberculous lymphadenitis.

Ghon’s focus

Ghon’s triad

* Fate:A. Good fate: - Healing by fibrosis and dystrophic calcification.- Formation of a dormant T.B focus.

B. Bad fate: Spread.1. Local.2. Lymphatic.3. Hematogenous 4. Natural passage. through the lumen of bronchi

2ry2ry PULMONARY T.B PULMONARY T.B

* Age: adults who are infected or vaccinated before.

* Mode of Infection:1. Reactivation of dormant focus.2. Exogenous by inhalation.

* lesions:• No complex formation.• It is only caseating tuberclous reaction (assman

focus or simon’s focus) develop at the apical portion of the lung.

• Not associated with lymphangitis or lymphadenitis.

• More in Rt. Lung than left lung.

Apical pulomnary T.B

* The Fate of 2ry pulomnary T.B:

A. Good fate:

- Regression and healing. In cases of good immunity.

B. Bad Fate:

- Progression and spread in cases of poor immunity.

1. Cavitary Tuberculosis

2. Chronic fibrocaseous pulmonary tuberculosis

3. Acute tuberculous bronchopneumonia & acute

caseous pneumonia.

Chronic fibrocaseous pulmonary tuberculosis

* Gross features:

1. Mother cavity: Large cavity formed at the apex of

the lung specially right lung due to caseation

necrosis of the apical lesions and its evacuation

into the bronchial tree to outside in the form of

sputum.

2. Daughter cavities (acinar lesions): Due to aspiration of the caseation necrosis through the bronchial tree to settle in the lower parts of the lung followed by cavitation.

3. Insignificant hilar lymphadenopathy.

* Microscopic examination:Extensive caseation necrosis form multipleCaseating tubercles healing by fibrosis,and calcification.

* Complications of chronic fibrocaseous pulmonary T.B:

1. Hemoptysis.2. Spontaneous pneumothorax & pyopneumothorax.3. 2ry amyloidosis.4. Peptic ulcer: 20% of cases; related to stress.5. Fibrosis: of the lung, bronchus & pleura leads to

bronchiectasis and pulmonary hypertension and.6. Spread.

ACUTE TUBERCULOUS BRONCHOPNEUMONIA & PNEUMONIA

• A rare complication of pulmonary T.B occurs with large doses of T.B bacilli and low immunity.

*Gross features:• The affected lung shows; multiple patches of

caseation necrosis around the bronchioles (bronchopneumonia) that rapidly progress leading to caseous consolidation of the alveoli leading to tuberculous pneumonia.

• The covering pleura shows tub. Pleurisy.• The Hilar L.Ns show Hilar tub. lymphadenitis.

*Microscopic features:• Extensive caseation, few epithelioid cells, few

langhan’s giant cells and no fibrosis.*Fate: rapidly fatal