Respiratory pathology 1
Lobar pneumonia
From: Stevens A. J Lowe J. Pathology.
Mosby 1995
An entire lobe is involved.
Fig. 17.1. In classical type, lobar pneumonia develops in four stages: (1)
congestion (serous alveolitis); (2) red hepatization (fibrinous alveolitis); (3)
gray hepatization (leucocytic alveolitis); (4) resolution.
Lobar pneumonia stage I (congestion)
From cases of the Pathology Department - U.M.F. “Gr. T. Popa” Iasi
Fig. 17.2. Serous alveolitis: (a) parieto-alveolar capillaries are congested;
(b) intra-alveolar serous exudate (intense eosinophilic material,rich in
proteins, which contains red blood cells and bacteria).
Lobar pneumonia stage II (Red Hepatization ) and III (Red Hepatization)
From: Stevens A. J Lowe J. Pathology. Mosby 1995
From cases of the Pathology Department - U.M.F. “Gr. T. Popa” Iasi
Fig. 17.3. Red Hepatization stage (II) and Fibrinous alveolitis: (a) parieto-alveolar capillaries are
intensely congested; (b) intra- alveolar fibrinous exudate, as a fibrin network, containing erythrocytes,
neutrophiles and infectious agents; fibrinous exudate passes through Kohn pores from an alveolus to
another (Mallory stain).
Fig. 17.4. Leucocytic alveolitis: (a) parieto-alveolar capillary network is still congested; (b) alveolar
lumen contains a suppurative exudate composed of neutrophils-PMNs and macrophages-Mfs.
Pulmonary carnification
From cases of the Pathology Department - U.M.F. “Gr. T. Popa” Iasi
Fig. 17.5.
Fig. 17.6
Fig. 17.5-6. Microscopy: It is a complication of fibrinous alveolitis stage
resulting by connective organization of the alveolar fibrinous exudate.
The alveolar lumen is occupied by a fibro-vascular granulation tissue
(connective vascular tissue of neoformation). (Simionescu staining)
Pulmonary abscess
From: Stevens A. J Lowe J. Pathology. Mosby 1995
Fig. 17.7. Pulmonary abscess: (1) the cavity: contains a suppurative material and air content (in
case of communication with air conducts); (2) wall: (a) acute abscess – the wall has irregular borders
reprezented by suppurative necrotic lung parenchyma; (b) chronic abscess - the wall is a pyogenic
membrane that becomes fibrotic by connective organization.
Bronchiectasis
From: Stevens A. J Lowe J. Pathology. Mosby 1995
Fig. 17.8. Multiple chystic lesions of varying sizes that extend to the pleura, and contain mucopurulent exudates. Affected bronchial walls are dilated and fibrotic, from where iradiates fibrous
bands within parenchimal lung.
Bronchopneumonia
From: Stevens A. J Lowe J. Pathology. Mosby 1995
From cases of the Pathology Department - U.M.F. “Gr. T. Popa” Iasi
Fig. 17.9.
Fig. 17.10
Fig. 17.9-10. Microscopy: (1) acute purulent bronchiolitis (purulent exudate
in the bronchial lumen and wall; the bronchiolar epithelium is altered and
exfoliated into the lumen); (2) peribronchiolar acute exudative alveolitis: (a)
leucocytic exudate; (b) fibrino-leucocytic exudate; (c) sero-fibrinous exudate.
Between nodular foci of bronchopneumonia the lung tissue is normal.
Bronchopneumonia of aspiration
From cases of the Pathology Department - U.M.F. “Gr. T. Popa” Iasi
Fig. 17.11
Fig. 17.12
It appears at newbornes with premature respiration during passage through mother borne channel
by aspiration of amniotic fluid (amniotic cells, epidermal descuamated cells, vernix caseosa – fat,
lanugo – hair, etc). Microscopy (HE): (a) Alveolar channels and alveolar spaces contain
hematoxilinic structures resembling with dry leaves (components of amniotic fluid) and serous
exudate with few neutrophils; (b) Congestion of capillaries into alveolar walls.
Pulmonary emphysema
From: Stevens A. J Lowe J. Pathology. Mosby 1995
From cases of the Pathology Department - U.M.F. “Gr. T. Popa” Iasi
Fig. 17.13
Microscopically, in PE, the lesions interest entire lung acinus
or lobule: (1) central acinus (BR); (2) peripheral lung acinus:
(a) alveolar channel and (b) alveolar sac.
Fig. 17.14
Fig. 17.3-4. Microscopy: (1) distention of air spaces (alveolar thin walls) and (2) destruction of alveolar
walls with fusion of adjacent alveolar lumens and formation of large air spaces. (3) Capillaries of alveolar
walls are compressed and reduced in number (pulmonary hypertension).