Histopathology: pulmonary pathology

Transcription

1 Histopathology: pulmonary pathology These presentations are to help you identify basic histopathological features. They do not contain the additional factual information that you need to learn about these topics, or all the images from resource sessions. This presentation contains images of basic histopathological features of various pulmonary pathologies (anthracosis, asthma, pneumonia). Pneumonia is a good example of an acute inflammatory process. Before viewing this presentation you are advised to review relevant histology, relevant sections on acute inflammation and pulmonary pathology in a pathology textbook, the histopathology power point presentation on acute inflammation, relevant lecture notes and relevant sections of a histopathology atlas. Copyright University of Adelaide 2011 (Med 1: Anthracosis and lymphatic drainage semester 1; pneumonia: semester 2 Med 2: Asthma and pneumonia semester 2)

2 Dust cells (black arrows): alveolar macrophages that have phagocytosed inhaled carbon. Similar cells containing haemosiderin pigment are seen in patients with chronic left heart failure (heart failure cells).

3 Dust cells (black arrows): alveolar macrophages that have phagocytosed inhaled carbon. These cells migrate in the lymphatics and are here seen in peribronchial tissue. Aggregates of these cells are seen as black spots macroscopically in the lung, a feature known as anthracosis. Many travel to the local hilar lymph nodes which also become black.

4 Acute asthma. Low power view of a mucus filled bronchus. Green stars: cartilage. Black star: mucus. Pale blue stars: seromucous glands. Yellow star: edge of hilar lymph node. Red star: cartilage of adjacent bronchus. Dark blue star: vein

5 Acute asthma. Medium power view of the edge of a mucus filled bronchus. Green star: cartilage. Black star: mucus. Blue star: seromucous glands. Yellow arrow: smooth muscle. Red arrows: epithelial basement membrane. Green arrows: respiratory epithelium. Black arrow: arteriole. Pale blue arrows: dilated venules. Dark blue arrows: capillaries

6 Acute asthma. High power view of the edge of a mucus filled bronchus. Black star: mucus. Red arrows: epithelial basement membrane. Green arrows: damaged respiratory epithelium. Yellow arrows: eosinophils

7 Most examples of lobar and bronchopneumonia result from bacterial infection causing acute inflammation. The inflammatory exudate includes neutrophils, fibrin and fluid. Lobar pneumonia, low power (above). Large expanse of lung where alveoli are filled with an inflammatory infiltrate. Black arrows: dilated venules. Yellow arrows: alveolar walls. In lobar pneumonia the alveoli of an entire lobe or the majority of a lobe is filled with inflammatory exudate and consolidated.

8 In bronchopneumonia, infection and inflammation spreads from bronchi and bronchioles into adjacent alveoli. Alveolar inflammation and consolidation are thus initially patchy (low power view above) and surround bronchioles.

9 In bronchopneumonia, infection and inflammation spread from bronchi and bronchioles. Bronchi and bronchioles are inflamed. High power (left image) and medium power (top image) of a bronchiole in bronchopneumonia. Black arrows: respiratory epithelium. Black stars: neutrophils in bronchiolar lumen. Green star: dilated congested venule. Yellow arrows: dilated congested capillaries. Red arrows: epithelial basement membrane.

10 Most examples of lobar and bronchopneumonia result from bacterial infection causing acute inflammation. The inflammatory exudate includes neutrophils, fibrin and fluid. On high power view above, neutrophils are seen filling the alveoli. Alveolar capillaries are dilated and congested with red blood cells.

11 Pneumonia, high power. Exudate filling alveolar spaces: neutrophils (black arrows), fibrin (black stars), macrophages (blue arrows) and extravasated red blood cells (yellow arrows). Note the relative sizes of cells. Neutrophils have a larger diameter than red blood cells (and lymphocytes - not seen here) and macrophages are often larger than neutrophils. The black line marks the alveolar walls, as indicated also by the capillaries and epithelial cells (red arrows).

12 Pneumonia, medium power. Alveoli are filled with neutrophils and homogenous eosinophilic oedema fluid (black star).

13 Fibrinous exudate (black star) on a serosal surface as is often seen in lobar pneumonia (on the pleura) due to acute inflammation of the underlying alveoli. This example is from acute appendicitis. The black lines represent the approximate location of the underlying serosal surface.

14 Pulmonary abscess (low power). Centrally there is necrotic debris and neutrophils (blue) with adjacent haemorrhage (red) in surrounding lung tissue.