R I = mucus gl / wall thickness Chronic Bronchitis Reid Index is the ratio of mucus gland layer to the thickness of the wall between the basement membrane & the cartilage R I = mucus gl / wall thickness Normally less than 0.4

Clinical Course of Chronic Bronchitis: 1. Persistent productive cough for 3 months in 2 consecutive years.( 3m x 2y ) 2. Eventually dyspnea on exertion develops 3. Later hypercapnea, hypoxemia & cyanosis. 4. Corpulmonale may develop in longstanding severe chronic bronchitis (due to hypoxia & destruction of lung parenchyma & hence fewer alveolar capillaries. This causes increased pulmonary arterial resistance & secondarily elevated pulmonary blood pressure).

Compare and contrast between bronchial asthma and chronic bronchitis as regards a) definition, b) clinical picture, c) pathogenesis and d) pathological features

They both are examples of obstructive lung disease Bronchial Asthma Chronic Bronchitis They both are examples of obstructive lung disease It is episodic and paroxysmal reversible bronchospasm (cough & wheeze) It is persistent productive cough for 3 months in 2 consecutive years The extrinsic form is type 1 hypersensitivity reaction however in both forms (ex. & intrinsic) the eosinophils play an important role It is due to irritation & inflammation of bronchial wall where T lymphocytes, macrophages, & neutrophils are concerned but no eosinophils. Goblet cell metaplasia or sq metaplasia Mononuclear inflammatory cell infiltrate but no eosinophils Marked hyperplasia of mucus gland layer (increased Reid index) Smooth muscle hyperplasia & peribronchial fibrosis Patchy necrosis & hyperplasia Eosinophilic & other inflammatory cell infiltrate Hyperplasia & hypertrophy of mucus glands Hypertrophy & hyperplasia of smooth muscle layer

Subepithelial collagen deposition Bronchial Asthma Subepithelial collagen deposition Chronic Bronchitis Squamous metaplasia

Bronchiectasis

Bronchiectasis It is permanent dilatation of bronchi & bronchioles due to destruction of the muscle & supporting tissue, resulting from or associated with chronic necrotizing or suppurative inflammation. C/P= cough+expectoration What is the lesion? What caused such lesion? What are the predisposing factors or the associated conditions?

Explain the pathogenesis of bronchiectasis

Pathogenesis of Bronchiectasis There are two processes involved in the pathogenesis .They are critical & intertwined Bronchial Obstruction e.g. by tumors, foreign body or excessive mucus Chronic necrotizing suppurative infection Or Inflammation throughout the bronchial wall with peribronchial fibrosis & scarring traction on the walls Impaired clearance of normal secretions Accumulation of secretions DILATATION of BRONCHI & BRONCHIOLES

Predisposing Conditions to Bronchiectasis: Childhood pneumonia &Tuberculosis

Predisposing Conditions to Bronchiectasis: To summarize Predisposing Conditions to Bronchiectasis: 1.Bronchial Obstruction: by a) tumours, b) foreign body ,and occasionally by c) mucus impaction. Under these conditions bronchiectasis is localized to the obstructed lung segment. Bronchiectasis can also complicate bronchial asthma and chronic bronchitis. 2.Congenital or hereditary conditions: In cystic fibrosis, widespread severe bronchiectasis results from obstruction and infection caused by abnormal viscid mucus. Kartagener syndrome, an autosomal recessive disorder with structural abnormalities of the cilia impairing the clearance of the mucus. 3.Necrotizing or suppurative pneumonia with virulent organism. In the past , post infective bronchiectasis was sometimes a sequel to childhood pneumonias that complicated measles, whooping cough , and influenza. Tuberculosis is an important cause of bronchiectasis.

Bronchiectasis Gross: lower lobes & bilateral. The distal bronchi & bronchioles : dilated and filled with mucopurulent secretions. The intervening peribronchial lung tissue show fibrosis.

Bronchiectasis Lower lobe affection (most common) Multiple dilated bronchi filled with purulent exudate The dilatation may be cylindrical, fusiform or saccular Fibrosis of the intervening lung tissue

Bronchiectasis Pleural fibrous adhesions between 2 lobes

Squamous metaplasia can occur Bronchiectasis Squamous metaplasia can occur Microscopic: Desquamation of surface epithelium causing extensive areas of ulceration is seen. Intense acute and chronic inflammatory cellular infiltrate is prominent. Fibrosis of bronchial wall and peribronchial tissue develop in more chronic cases.

Bronchiectasis

Bronchiectasis Bronchogram

Bronchiectasis Pulmonary CT showing Tramlines & signet ring appearance of dilated bronchi

Bronchiectasis Pulmonary CT showing Tramlines & signet ring appearance of dilated thick walled bronchi due to peribronchial fibrosis

Traction Bronchiectasis

Clinical Course of Bronchiectasis: Severe persistent cough with expectoration of mucopurulent sometimes foul smelling or bloody sputum. The cough is paroxysmal in nature especially in the morning or on changing the position due to draining of the accumulated purulent secretions. Symptoms may be episodic & are precipitated by upper respiratory tract infections with introduction of new pathogen.

Complications of Bronchiectasis Haemoptysis (due to erosion of a nearby blood vessel). Lung abscess & lung gangrene. Malignant transformation to bronchogenic carcinoma due to squamous metaplasia and dysplasia. Pleural complications as empyema, pneumothorax , pyopneumothorax ,and bronchopleural fistula. Cor pulmonale due to excessive fibrosis that leads to pulmonary hypertension. Direct spread of infection leading to mediastinitis & pericarditis. Acute toxaemia, septicaemia ,& systemic pyaemia leading to brain abscess. Amyloidosis.

Complications of Bronchiectasis 1.Haemoptysis 2. Pleural complications 5. Direct spread to mediastinum 3. Lung abscess & gangrene 4. Malignant transformation 6. Corpulmonale due to fibrosis & pulmonary hypertension 7. General : Acute toxaemia, septicaemia , pyaemia & Amyloidosis

You can tabulate your answer. Cough with expectoration can be a presenting symptom for the 3 diseases you have taken today in this lecture (Bronchial Asthma, Chronic Bronchitis & Bronchiectasis) how can you differentiate between them as regards: a) definition, b) pathogenesis, c) additional symptoms and signs, d) Pathological features, and e) complications You can tabulate your answer.

A man complained of attacks of cough with expectoration for 5 years that increase during winter. He has been smoking since 8 years. What is the possible diagnosis? A man complained of mild dyspnea and cough when he was exposed to irritant gas fumes which was relieved spontaneously. What is the possible diagnosis? A man complained of cough & expectoration of a large amount of purulent sputum early in the morning after rising from the bed. What is the possible diagnosis? Mucus plugs + hyperplasia in mucus glands ??? Mucus plus + marked smooth muscle hyperplasia Mucus plugs + hyperplasia in mucus glands with increase in Reid index Mucus plugs + basement membrane thickening by collagen Ulceration, mucopurulent exudate dense acute and chronic inflammatory cellular infiltrate and peribronchial fibrosis ??? Mucus plugs + eosinophilic and mast cell infiltration Dilated distal bronchi with ulceration, mucopurulent exudate dense acute and chronic inflammatory cellular infiltrate and peribronchial fibrosis

By the end of this lecture you will be able to: Define bronchial asthma and differentiate between its extrinsic & intrinsic types. Explain the pathogenesis of each type Describe the pathological features of bronchial asthma Define chronic bronchitis and list its possible types. Describe the pathologic features of chronic bronchitis. Compare & contrast the pathologic features of simple chronic bronchitis and extrinsic bronchial asthma. Define bronchiectasis and state its clinical manifestation. List the most frequent conditions associated (predisposing factors) with bronchiectasis Describe the pathologic characteristics of bronchiectasis. Enumerate the complications of bronchiectasis