Emphysema

Presented By:Aamir Sharif

M.Phil Human Pathology & MicrobiologySMC

Definition

• Emphysema is abnormal permanent enlargement of air spaces distal to terminal bronchioles accompanied by destruction of their walls without obvious fibrosis

• Emphysema may be pure but in majority of cases it is accompanied by chronic bronchitis

Types

Centriacinar emphysema

• The central parts of acini formed by respiratory bronchioles are affected

• Most common in upper lobes in smokers

Panacinar emphysema

• Acini are uniformly enlarged from resp . Bronchiole to alveoli

• Tend to occur more commonly in lower lung lobes in @1-antitrypsin deficiency.

Types Cont..

Distal acinar emphysema (paraseptal)

• The proximal portion of the acinus is normal but distal part is involoved.

• Localized along the pleura, adjacent to perilobular septa

• More severe in upper half of lung

• Bullae formation (multiple, contigous, enlarged airspaces <0.5 mm>2.0 cm cyst like structure)

irregular emphysema

• Acinus is irregularly involved.

• Associated with scarring• Resulting from healed

inflammatory disaese.• Often asymptomatic

PATHOGENESISPROTEASE -ANTI PROTEASE IMBALANCE

• In serum proteinase inhibitors are present esp. antielastase (alpha 1 antitrypsin encoded by genes chr. 14.) which prevent the destruction of elastic tissue by the enzyme elastase

• This hypothesis is based on observation that more than 80% of individuals with @1 antitrypsin deficiency develop emphysema.

Cont..• In smokers , macrophages and

neutrophils accumulate in alveoli which are rich in elastases.

• Nicotine and reactive oxygen species in smoke deplete antioxidants and activate IL-8, LTB4, TNF

• Activated granules release Elastase Proteinase 3 Cathepsin G• Smoking also inhibit alpha 1

antitrypsin & thus decreases net antielastase activity in smokers.

GROSS MORPHOLOGY

• Panacinar emphysema when well developed produces Pale voluminous lungs

• The lungs are Deeper pink, less voluminous

• Upper two thirds of lungs are more severely affected

Panacinar

MORPHOLOGY• Histologically, there is thinning and destruction of

alveolar walls.• With advanced disease adjacent alveoli become

confluent, creating large airspaces.

• Terminal and respiratory bronchioles may be deformed bc of loss of septa.

• Small airways tend to collapse during expiration due to loss of elastic tissue in septa which reduces radial traction on the small airways.(an important cause of chronic airflow obstruction in severe emphysema)

CLASSIC PRESENTATION

• Individuals who have no bronchitic component are barrel shaped chest and dyspnea , with prolonged expiration.

• Patient over ventilate & remain well oxygenated, called Pink Puffer

• Characteristic posture…sitting forward in hunched over position attempting tosqueeze air out of lungs with each expiratory effort.

• Patients WITH BRONCHITIC COMPONENT have less prominent dyspnea and respiratory drive ,so they become hypoxic , retain CO2,and are often cynotic.

• Often they seek help after onset of cor pulmonale and associated edema. Patients with this clinical picture are called BLUE BLOATERS.

Diagnosis

SpirometryReduced FEV1 with normal or

near normal FVC

CXR shows1. A chest X-ray demonstrating severe

COPD. Note the small size of the heart in comparison to the lungs.

2. A lateral CXR of a person with emphysema. Note the barrel chest and flat diaphragm

3. Lung bulla as seen on CXR in a person with severe COPD associated with anti 1 antitrypsin deficiency

4. Bullous emphysema5. Bullus emphysema as seem on CT

A chest X-ray demonstrating severe COPD. Note the small size of the heart in comparison to the lungs.

A lateral CXR of a person with emphysema. Note the barrel chest and flat diaphragm

Lung bulla as seen on CXR in a person with severe COPD associated with anti 1 antitrypsin deficiency

Bullous emphysema

Bullus emphysema as seem on CT