1. Assistant professor of pathology
Pneumonia By
Dr. Abdelaty Shawky
Assistant professor of pathology

2. PNEUMONITIS

3. * Classification:
1. Bacterial pneumonia: lobar pneumonia & bronchopneumonia.
2. Viral (interstitial) pneumonia: influenza, measles, chicken pox.
3. Loeffler’s (parasitic) pneumonia: Bilharziasis, ascaris & ankylostomiasis.
4. Granulomatous pneumonia: T.B, sarcoidosis, leprosy, syphilis, actinomycosis .
5. Lipoid pneumonia: due to aspiration of oily nasal drops.
6. Irradiation pneumonia.

4. LOBAR PNEUMONIA

5. * Def: acute diffuse fibrinous inflammation of one or more lung lobes.
* Etiology:
Age: middle age.
Predisposing factors: low resistance.
Causative organism: pneumococci.
Route of infection: droplet infection.

6. * Pathogenesis:
Pneumococci are inhaled to reach alveoli. They cause acute inflammaion with excess fluid exudate. This fluid exudate pass from one alveolus to another rapidly through the inter- alveolar pores of cohn to involve the whole lung lobe. The fluid exudate expel air away from the alveoli producing a firm airless lobe leading to consolidation (hepatisation) of the affected lobe.

7. 1. Duration 2. Gross Picture: the affected lobe is
4. Stage of resolution
3. Stage of gray hepatization
2. Stage of red hepatization
1. Stage of congestion
1. Duration
9th – day 21
5th – 8th day
2nd – 4th day
1st day
2. Gross Picture: the affected lobe is
- Since there is no necrosis, healing by resolution occurs.
- Enlarghed.
- Gray.
- Consistency: consolidated (hepatized).
- Cut section: dry.
- Pleurisy.
- Enlarged hilar LNs.
- Enlarged.
- Red.
- Size: Enlarged.
- Color: Red.
- Consistency: like wet sponge.
- Cut section: exudes frothy fluid.
- The covering pleura: normal
- The hilar L.Ns.: normal

8. Lobar pneumonia of upper lobe

9. Lobar pneumonia of the lower lobe

10. 3. Stage of gray hepatization 2. Stage of red hepatization
4. Stage of resolution
3. Stage of gray hepatization
2. Stage of red hepatization
1. Stage of congestion
3. Microscopic Picture
a. Alveolar capillaries:
Less congested
b. Alveolar walls: thin.
c. Alveolar spaces:
Show dead bacteria, shrinked fibrin, hemolysed RBCs, excess polymorphs and macrophages.
Congested.
b. Alveolar walls: thickened.
Show bacteria, fibrin, RBCs and polymorphs.
Show bacteria & fluid exudate.

11. Lobar pneumonia; red hepatization

12. Lobar pneumonia; grey hepatization

13. 3. Stage of gray hepatization 2. Stage of red hepatization
4. Stage of resolution
3. Stage of gray hepatization
2. Stage of red hepatization
1. Stage of congestion
4. Clinical course
- Fever, cough, dyspnea and chest pain.
- At about 9th day the disease ends by crisis (sudden improvement), however death may occur due to severe toxaemia.

14. 3. Stage of gray hepatization 2. Stage of red hepatization
4. Stage of resolution
3. Stage of gray hepatization
2. Stage of red hepatization
1. Stage of congestion
5. Complications
Spread of infection: direct, lymphatic and blood (toxaemia, septicaemia).
Lung fibrosis due to failure of resolution.
Post-pneumonic lung abscess.

15. BRONCHOPNEUMONIA

16. * Def: Acute suppurative inflammation of bronchioles and adjacent alveoli characterized by patchy lung consolidation.
* Etilogy:
Age: extremes of age (young & elderly).
Predisposing factors: low resistance and bronchitis.
Causative bacteria: staphylococci, streptococci & H. influenza.
Route of infection: endogenous invaders and exogenous invaders (droplet infection).

17. * Gross picture:
Bilateral.
Basal.
Multiple consolidated yellowish patches exuding pus on pressure. Several patches may coalesce to produce confluent bronchopneuomonia.
Enlarged hilar L. nodes.

18. Bronchopneumonia

19. Bronchopneumonia

20. * Microscopic Picture:
I. The broncioles show:
Their lumen shows: necrotic epithelial cells, polymorphs & pus cells.
Their lining: ulceration.
Their walls: congested capillaries, neutrophils and pus cells & exudate.
II. The adjacent alveoli show: 3 successive zones: zone of alveolitis then zone of alveolar collapse and a zone of alveolar dilatation (compensatory emphysema).

22. * Complications:
Spread of infection: direct, lymphatic and blood (toxaemia, septicaemia).
Lung fibrosis due to failure of resolution.
Post-pneumonic lung abscess.
Bronchiectasis.

23. Thanks