Pathology of lung

Atelectasis

Loss of lung volume due to inadequate expansion of air spaces

1. Resorption

2. Compression/passive/relaxation/flaccid

3. Contraction /Cicatriztion

4. Non obstructive/micro

Acute lung injury

Spectrum of endothelial and epithelial pulmonary lesions

Acute onset of dyspneaB/l pulmonary edemaHypoxemiaNo LHFPathology of vasculature- alveolar

capillary membrane damage Non cardiogenic pulmonary edema

Acute injury can be

1. Direct injury- Pneumonia,aspiration of gastric contents

2. Indirect injury- sepsis,severe trauma with shock

3. A/c injury----------- ARDS

ARDS

Diffuse alveolar capillary and epitrhelial damage

1. Respiratory insufficiency

2. Cyanosis

3. Severe arterial hypoxemia-not responding to oxygen therapy

4. Progress to mutisystem organ failure Neutrophils hav a imp role in ARDS

Destructive forces are counter acted by anti proeases, oxidents ,etc

Degree of tissue injury depends on balance of two

Emphysema

1. Centri acinar/centri lobar- in smokers-

2. Pan acinar/pan lobar- ass. With alpha 1 anti trypsin deffi.

3. Distal acinar/para septal- adj. to scarring, fibrosis,atelectasis

4. irregular- associated with scarring- assymptomatic

C/C Bronchitis

Persistent productive cough for 3 consecutive months for 2 consecutive years

Three types1. Simple c/c bronchitis-productive cough—

mucoid sputum—air flow not obstructed2. C/C asthmatic bronchitis-hyper responsive

airways—intermittent bronchospasm and wheezing

3. C/C obstructive bronchitis-associated with emphysema

Asthma

Air way remodeling ADAM33

1. Thickening of basement membrane of bronchial epithelium

2. Edema & inflammatory infiltrate in the bronchial walls,with a prominnce of eosinophils and mast cells

3. An increase in size of submucosal glands

4. Hypertrophy of bronchial smooth muscles

Bronchiectasis

Pneumonia

Two types

1. Broncho

2. Lobar Mostly occurs by aspiration of

pharyngeal flora Lower lobes/ right middle lobes are

mostly affected

1. Community- acquired Acute pneumonia-pyogenic org.

2. Community acquired atypical pneumonia-virus, mycoplasma, candida

3. Nosocomial- pseudomanas,gram neg.

4. Aspiration – anerobic

5. Chronic – Mtb

6. Necrotizing pneumonia and lung abcess-Anerobic + pyogenic

7. Pneumonia in the immunocompramised host – chlamydia, aspergillosis, CMV

Complications of pneumonia

Lung abscess Empyema- suppurative materials may

accumulate in the pleural cavity Bacterial dissemination leading to

meningitis,arthritis, infective endocarditis Complications are much more with

serotype 3 pneumococci

Atypical pneumonias

Acute febrile respiratory d/s characterized by patchy consolidation of lungs, largely confined to alveolar septa and pulmonary interstitium

Atypical-moderate amounts of sputum, absence of physical finings of consolidation,only moderate inc in WBC coun,lack of alveolar exudate

Mostly by Mycoplasma pneumoniae

Lung Abscess

Suppurative destruction of lung parenchyma with central area of cavitation

Good Pasture’s syndrome

RPGNHaemorrhagic interstitial pneumonitis

Lung tumours

1. Squamous cell carcinoma/epidermoid carcinoma

2. Adinocarcinoma-bronchial derived, acinar,papillary,broncioloalveolar,solid

3. Small cell carcinoma-oat cell, intermediate

4. Large cell carcinoma,undiff,giant cell, clear cell

5. Others- combined small cell carcinoma,Adenosquamous carcinoma

Adenocarcinoma has replaced SCC as the most common primary lung tumour

Most common in women,non smokers,persons younger than 45yrs

Therapeutic classification

1. Small cell lung cancer (SCLC)

2. Non small cell lung cancer (NSCLC)