Chronic congestion of the lung (brown induration) (302)

Chronic LVF - impairment of the exit of the blood from the lungs Increased pressure in the alveolar capillaries Microhemorrhages into the alveoli, red blood cells are phagocytosed by

macrophages (heart failure cells) (macrophages laden with hemosiderin)

Fibrosis of the interstitial spaces of the lung Lung is brown and firm brown induration Consequences of higher pressure in capillaries is pulmonary

hypertension, which may lead to right heart failure.

spaces filled by air (might be filled by edematous fluids)

Coal dust (Black irregular spots)

Heart failure cells (Single cells containing dark dots)

alveolar walls

Emphysema of the lung (2)

Chronic lung disease characterized by permanent enlargement of the airspaces

Visible enlargement of the airspaces.

major cause cigarette smoking (protease-antiprotease theory)

Alpha-1 antitrypsin (1-AT) deficiency 1% cases

Emphysema is classified according to the location of the lesions within the pulmonary acinus: Centriacinar (Centrilobular) Panacinar (Panlobular) Paraseptal Irregular

Ruptured alveoli, forming large airspaces (less surface area)

Coal dust (smoking?)

Pores of Kohn

Bronchus?

Bronchopneumonia (303)

Caused by infection of air way (trachea, bronchi) Streptococci, staphylococci Multifocal changes Four stages, but we can observe different stages in every focus.

Pneumonia has 4 stages: Congestion Red hepatization Gray hepatization Resolution

macro: multifocal changes. Inflammations are yellow. Usually complication of bronchitis. Slide:

Normal area: some fluid in normal area (septa visible). Inflamed area: Septa almost invisible (lots of cells in exudate

compresses the septa). Bronchi filled by pus (inflammation start in bronchi, then involves other areas) (neutrophils, cellular debris).

Lots of rbc and neutrophils

Bronchioles filled with pus

Interstitial pneumonia (305)

The most common cause is viral infection of the lung CMV, Varicella, HSV Viruses affect the alveolar epithelium and cause mononuclear infiltration

Children, elderly patients Often asymptomatic, no changes in x-ray picture

Dilated interstitial parts of the lung, airspaces preserved Symptoms: cough for a long time. Reduced lung capacity.

Necrosis of type I epithelial cells and hyaline membranes formation Morphology: no circumscribed changes. More yellow areas suspected (in

autopsy sample). Newborn might die from interstitial pneumonia slide: thickened septa containing cells (Inflammatory cells (lymphocytes,

plasma cells). Dilated capillaries. Hyaline membrane covers septa wall (from necrotic debris of injured cells). Can cause death when large areas covered. Bronchi normal with no infiltration.

Wide bronchoalveolar septa filled with inflammatory cells

Necrotic debris on wall of septa, forming hyaline membranes. Serious state

Enlarged capillary in septa filled with blood cells

Empty alveolar spaces

Artery?

No infiltration in bronchus

Fibrocaseous tuberculosis of the lung (306)

Caused by Mycobacterium tuberculosis Inhaled M. tuberculosis is deposited in the alveoli, usually in the

lower and middle lobes and anterior segments of upper lobes. Generally is transmitted from person to person by aerosolized

droplets Caseous granuloma - Classic lesion of tuberculosis

Soft, semisolid core surrounded by epithelioid cells, Langhans giant cells, lymphocytes and peripheral fibrous tissue Caseous necrosis in center

This is why this form of tuberculosis is called fibrocaseous tuberculosis

Gross: large nodule (white, chalky appearance), caseous necrosis. Granuloma at the edge.

Slide: Edges of necrosis fibrosis (fibrous connective tissue surrounds granulomas). Lesions are large (unlike in miliary tuberculosis)

Large area of necrotic debris

Langhans giant cellepithelioid cells

Inflammatory infiltrates

Tuberculoma (319)

Firm, round tumor (not neoplastic) Lung, meninges Solitary mass with central caseous necrosis surrounded by granulomatous tissue Encapsulated Can form when treating tuberculosis. If treatment stops, new granuloma forms

around healing areas (fibrotic areas). Up to 10 cm. Looks like malignant tumor. In tumor with central necrosis, need to check border to determine cell type to

differentiate form neoplasm.

Slide: part of slide pink, other area darker. Large, light pink area = necrosis. Many new, small granuloma around large area of necrosis. Epithelioid cells (elongated nucleus). Can be layers of necrosis mixed with layers of fibrosis

fibrosis

Necrosis (old granuloma)

New granuloma on the edge

Sarcoidosis of the lung (313)

Worldwide disease affecting all races and sexes Causes are multifactorial environmental and genetic (BTNL gene) lung, lymph nodes, spleen, liver, skin, uveal tract, bone marrow Granulomatous inflammation

No caseous necrosis multiple, sarcoid granulomas are scattered in the interstitium of the lung granuloma lymphocytes, giant cells, epithelioid cells (macrophages) Asteroid bodies (star shaped crystals) may be seen Schaumann bodies (small calcifications with a laminar structure) may be present

inside Langhans cells. slide: lymphocytes on the edges, central part with epithelioid cells (not just on the

edge like regular granuloma). Giant cells. Many granulomas.

Silicosis of the lung (323)

Caused by the inhalation of silicon dioxide Silica particles are ingested by alveolar macrophages Macrophages are destroyed by silica particles dead cells release free silica particles and fibrogenic factors fibrogenic factors form nodules of collagen fibers.

Usually slowly progressing, nodular, fibrosing pneumoconiosis. Silicotic nodule is composed of concentric whorls of dense, sparsely cellular collagen Infiltration composed of lymphocytes and macrophages At the edge of the nodule dust with carbon pigment and silica particles

silica particles are hard to see Slide: nodule surrounded by chronic inflammatory cells (Coal dusts, macrophages,

lymphocytes). Few cells in nodule (collagen fibers).

Whorl of collagen

Chronic congestion of the lung (brown induration) (302)Emphysema of the lung (2)Bronchopneumonia (303)Interstitial pneumonia (305)Fibrocaseous tuberculosis of the lung (306)Tuberculoma (319)Sarcoidosis of the lung (313)Silicosis of the lung (323)