FLASHPATHH a z e m A l i

CHRONIC BRONCHITIS

H a z e m A l i

CLINICAL

Chronic bronchitis is one of the “obstructive lung diseases” that include:• Emphysema

• Bronchiectasis

• Small-airway disease “bronchiolitis”

• Asthma

CLINICALObstructive airway

diseaseRestrictive airway

diseaseGeneral features Increase in resistance to

airflow due to obstruction at any level

Reduced expansion of lung parenchyma

Total lung capacity (TLC)

Increased Reduced

Forced Expiratory Volume in one second (FEV1)

Reduced Normal

CLINICAL• Emphysema and chronic bronchitis are often clinically

grouped together and referred to as chronic obstructive pulmonary disease (COPD)

• COPD is the 3rd leading cause of global death

• Usually due to cigarette smoking and air pollution

• Usually present in adults (> 45 years old) and more common in males

• Main symptom are dyspnea and cough

CLINICALPredominant Chronic

BronchitisPredominant Emphysema

Age 40 – 45 years old 50 – 75 years oldAppearance Blue Bloater Pink Buffer

Dyspnea Mild, Late Early, SevereCough Early

Copious sputumLate

Scanty sputumInfections Common Occasional

Respiratory Insufficiency

Repeated Terminal

Cor pulmonale Common Rare, TerminalRadiology Prominent vessels

Large heartHyperinflation

Small heartAirway Resistance Increased Normal or slightly

increasedElastic Recoil Normal Low

CLINICAL• Chronic bronchitis is:

– Chronic disease of large airways– Persistent “productive” cough– For at least 3 months– In at least 2 consecutive years– Without other apparent explanation

CLINICALLines of treatment:• Smoking cessation• Medications (Bronchodilators, Steroids)• Oxygen therapy and Ventilatory support• Antibiotics (for 2ry infections)• Lung transplantation (for end-stage diseases)

Main causes of death:• Coronary artery disease• Respiratory failure• Right-sided heart failure

PATHOGENESIS

SmokingAir pollution(initiate bronchitis)

• Interferes with ciliary action• Directly damages airway

epithelium• Inhibits ability of white blood

cells to clear bacteria

Infection(maintain bronchitis)

GROSS• Bronchi:

– Dilated– Filled with excessive mucus / pus

• Lung parenchyma:– Anthracosis– Emphysema

MICROSCOPYBronchi:• Mucus hypersecretion• Hypertrophy of submucosal glands

– Increased Reid index• Goblet cell hyperplasia• Squamous metaplasia, Dysplasia• Chronic inflammation

– No eosinophils

MICROSCOPYReid index• Ratio of

REMEMBER:• Measured at main or lobar bronchi• The epithelium should be parallel to the cartilage• Normal index up to 0.4• Chronic bronchitis > 0.4 (average 0.6)

MICROSCOPY• Other Smoking-related conditions:

– Anthracosis– Emphysema– Desquamative interstitial pneumonia– Respiratory bronchiolitis– Pulmonary eosinophilic granuloma

• “Langerhans cell histiocytosis”– Usual interstitial pneumonia

• Pulmonary hypertension

CYTOLOGYBenign bronchial cell changes1. Reactive changes

– Columnar, ciliated bronchial cells– Nuclear enlargement– Coarse chromatin– Prominent nucleoli

2. Creola bodies– Spherical 3D Clusters– Columnar, ciliated bronchial cells– Also seen in Asthma

• Charcot-leyden crystals• Curschmann's spirals• Eosinophils

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CYTOLOGY3. Goblet cell hyperplasia

– Large sheets or round clusters– Composed almost exclusively of goblet cells

• Abundant mucin-filled cytoplasm– Benign columnar, ciliated bronchial cells are also seen

• The bronchi are lined with ciliated or columnar epithelium with scattered gobletcells. Goblet cell hyperplasia is an indication of irritation, such as in bronchitis or asthma

Benign bronchial cells changes can mimic Adenocarcinoma:– LOSS OF CILIA– Do not rush for calling adenocarcinoma on just few small group of cells

• Especially with inflammatory background OR history of COPD, Asthma– Reactive changes resolve within 1 month wait and repeat cytology

CYTOLOGYOther injury-associated findings1. Bronchial reserve cell hyperplasia

– Tightly packed small cells – Scant cytoplasm– Smudged dark chromatin– Nuclear molding may be seen– No mitoses or necrosis

Bronchial reserve cell hyperplasia can mimic Small cell carcinoma:– LESS COHESIVE– MARKED MITOSIS / NECROSIS– CLINICAL HISTORY

CYTOLOGYOther injury-associated findings2. Reparative “re-epithelialization” of respiratory tract

– Flat, cohesive sheets– Abundant cytoplasm– Enlarged nuclei– prominent nucleoli– Mitoses

Reparative epithelium can mimic Non-Small cell carcinoma:– LESS COHESIVE– MARKED MITOSIS / NECROSIS– CLINICAL HISTORY

DIFFERENTIAL DIAGNOSIS

Chronic bronchitis

Bronchiectasis Asthma

Small-airway disease

“bronchiolitis”

Emphysema

Site B r o n c h u s Bronchioles AlveoliMajor

pathology

• Mucous gland hyperplasia

• Excess mucus

• Inflammation

• Airway dilation & scarring

• Thickened basement membrane

• Smooth muscle hyperplasia

• Excess mucus

• Inflammation(eosinophils)

• Inflammatory scarring & obliteration

• Airspace enlargement

• Wall destruction

• No fibrosis

Other obstructive lung diseases:

DIFFERENTIAL DIAGNOSISChronic Bronchitis Bronchial Asthma

Age Usually adults Any ageSmoking history Almost invariable PossibleCough Persistent

ProductiveIntermittentNon-productive

Breathlessness Persistent IntermittentNocturnal symptoms Uncommon CommonFamily history Uncommon

“unless family members smoke”

Common

Other allergic diseases Uncommon Common“eczema or allergic rhinitis”

Airflow obstruction Irreversible ReversibleSputum Macrophages

NeutrophilsCreola bodies

EosinophilsCharcot–Leyden crystalsCurschmann’s spiralsCreola bodies

DIFFERENTIAL DIAGNOSISChronic Bronchitis Bronchial Asthma

Gross Excess mucusBronchial dilatationAssociated emphysema

Mucous plugsHyperinflation but no emphysema

Airway inflammation CD8+ T cellsNeutrophils periodically

CD4+ T cellsEosinophilsMast cells

Airway epithelium IntactGoblet cell hyperplasiaSquamous metaplasia

Fragile with strippingGoblet cell hyperplasiaSquamous metaplasia

Basement membrane thickening

Mild to moderate Marked

Bronchial glands enlargement

Marked Moderate

Airway muscle hypertrophy

May be seen Marked

Major complications Cor pulmonale Allergic bronchopulmonary aspergillosis

DIFFERENTIAL DIAGNOSISOther causes of chronic cough• Lung carcinoma• Bronchiectasis• Cystic fibrosis• Congestive heart failure• Tuberculosis

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