Diseases of the Lung and Respiratory Tract Part

Pulmonary Pathology II 

William Bligh-Glover M.D. 

Department of Anatomy, CWRU

Goals and Objectives 

• Comprehend the etiology, 

pathogenesis/pathopysiology and 

consequences of pulmonary hypertension 

• Distinguish the types of lung infection, and 

comprehend their etiologies, 

epidemiology, pathogenesis and prognosis 

• Comprehend the etiology, 

pathogenesis/pathophysiology and 

consequences of lung abscess

Pulmonary Hypertension 

• Defined as at least 25% of systemic pressure; 

normal is 10% of systemic, due to low resistance 

of pulmonary vasculature 

• Hypertension usually due to structural diseases 

causing increased pulmonary blood flow or 

pressure, increased pulmonary vascular 

resistance or left heart resistance 

• Note: pulmonary atherosclerosis implies there is 

pulmonary hypertension


• Emphysema 

– Hypoxia and alveolar destruction reduce the number of 

capillaries, causing increased arterial resistance, 

• Congenital heart disease 

– Elevated pressures due to valvular disease 

• Recurrent PE 

– Reduced area of vascular bed with consistent pressures 

• VOD 

• Fenfluramine/phenterimine 

• Idiopathic 

– Decreased production of nitric oxide and prostacyclin and 

increased levels of endothelin, leading to endothelial cell 

activation and thrombogenesis 

– Women 20-40


• Treatment 

– vasodilators, calcium channel blockers, nitric 

oxide, anti-thrombotic medications 

• Consequences 

– Right heart hypertrophy (Cor pulmonale) 

– Dyspnea 

– Pneumonia

Recurrent PE

Plexiform Lesions

Cor Pulmonale Cartoon

Cor Pulmonale Gross


• Consequences of pulmonary hypertension 

– Pulmonary atherosclerosis 

– Recurrent thromboemboli 

– Intimal thickening 

– Plexiform lesions 

• Reversible/Irreversible 

– Reversible if arterial lesions restricted to medial 

hypertrophy, intimal thickening of longitudinal smooth 

muscle or cellular intimal proliferation 

– Irreversible if moderate/severe concentric laminar 

intimal fibrosis, fibrinoid necrosis, plexiform lesions

Non-Infectious Diseases Leading to 


• Acute Interstitial Pneumonia (AIP) 

• Bronchiolitis Obliterans Organizing 

Pneumonia (BOOP) 

• Desquamative Interstitial Pneumonia (DIP) 

• Usual Interstitial Pneumonia (UIP)

Acute Interstitial Pneumonia 

• Also called Hamman-Rich syndrome 

• Rapidly progressive disease with no 

identifiable cause; death usually within 2 

months 

• Young adults with influenza-like illness 

followed by shortness of breath 

• Micro: resembles diffuse alveolar damage 

with brisk interstitial fibroblastic 

proliferation

Bronchiolitis Obliterans-Organizing 

Pneumonia 

• Common response to infectious or inflammatory 

injury to lungs 

• Also associated with drugs, collagen vascular 

disease, graft versus host disease in bone 

marrow transplant patients 

• Cause cannot be determined from biopsy - 

requires clinical history 

• Acute onset with cough, shortness of breath, 

fever and malaise 

• Excellent prognosis; steroid resistance may lead 

to death

Desquamative Interstitial 

Pneumonitis 

• Usually adults with insidious onset of shortness 

of breath, progressing to respiratory 

insufficiency; also cough, cyanosis, clubbing 

• Cause unknown 

• Mean survival 12 years, mortality 28% 

• 90% are current or past cigarette smokers 

• Associated with collagen vascular disease, 

positive ANA (similar to UIP) 

• Treatment: steroids (respond better than UIP)

Usual Interstitial Pneumonitis 

• Most common pattern of idiopathic pulmonary fibrosis 

• Usually ages 50+ 

• 50% have unknown cause with insidious onset 

(exertional dyspnea) and chronic evolution; 

complications include secondary pulmonary 

hypertension, cor pulmonale, cardiac failure 

• Reduced diffusing capacity is mainly due to ventilationperfusion 

mismatch from ventilation of lung tissue with 

capillary destruction and perfusion of under ventilated 

alveoli 

• Treatment: steroids (20% improve) 

• Mean survival 6 years, mortality 66%

• Bacterial 

Pulmonary Infections 

– Pneumococcus 

– Mycobacterial 

–CF 

– Aspiration 

•Viral 

• Mycoplasma 

• Fungal

Pneumonia 

• “Old Man’s Friend”—Final common pathway 

• Lung is #1 site for infections that cause lost workdays 

• Impairment of defense mechanisms or host resistance 

– Normal defense mechanisms: 

• Nasal clearance (sneezing, blowing, swallowing) 

• Mucociliary elevator (smoking) 

• Alveolar clearance (alveolar macrophages) 

– Host resistance 

• Age 

• Intoxication 

• Other diseases 

• Bronchopneumonia vs. Lobar pneumonia 

– Bronchopneumonia 

• Patchy consolidation of the lung centered on bronchi 

• Neutrophils in bronchi, bronchioles and adjacent alveolar spaces 

– Lobar pneumonia 

• Consolidation of entire lung 

• Rare because of antibiotics 

• Vulnerable patients 

– Old 

– Young 

– Drunks 

• Congestion, red hepatization, grey hepatization, resolution

Pneumococcus 

(Streptococcus pneumoniae) 

– Gram positive, capsulated, lancet-shaped 

diplococcus 

– Respiratory flora 

– Pneumonia, Otitis media, Meningitis

Bronchopneumonia Gross

Bronchopneumonia Low Micro

Bronchopneumonia High Micro

Lobar Pneumonia

Pneumococcus

Final Common Pathway 

• “Old Man’s Friend” 

• Impairment 

– Viral pneumonia 

– Breaking hip

Tuberculosis 

• A.K.A. Consumption, commonest infectious COD in Operas 

– Mycobacteria tuberculosis 

– Mycobacteria bovis 

• Lung involvement is the major cause of morbidity/mortality 

– Rarely involves skin, oropharynx, lymphoid tissue 

– Pott’s disease (TB of spine) 

– Prosector’s wart (TB of hand) 

• Suppressed by cell mediated immunity, therefore 

– Cases increasing due to AIDS 

– There have been emergence of multiple-drug resistant strains 

– Impaired patients not completing a course of antibiotics 

• Treated with months of antibiotics (INH, Rifampin) 

• Streptomycin in the early days

Mycobacterium tuberculosis 

• Acid-fast, slow growing bacillus 

• Aerobe 

• Two organisms 

– M. tuberculosis 

– M. bovis

Mycobacterium tuberculosis

Gohn Complex 

• Gohn complex 

– Parenchymal coin lesion 

• Subpleural 

• Near upper/lower lobe interlobar fissure 

• High oxygen tension) 

– Caseous lymph nodes 

– Resolution 

• Fibrosis 

• Calcification 

• Asymptomatic

Gohn Complex

Reactivation (Secondary) TB 

• 5-10% of cases of primary infection 

• Produces more damage than primary TB 

• Apical areas of consolidation with caseous 

necrosis in draining nodes 

• Usually get progressive fibrous encapsulation, 

which causes focal pleural adhesions, may 

contain anthracotic pigment 

• Tubercles coalesce over time, creating confluent 

area of consolidation

TB Granuloma

TB Granuloma High Power

Saranac Lake

La Boheme

•Not Military TB 

Miliary TB 

• Looks like lung is shot through with millet 

seeds 

• Progressive spread in compromised 

individuals

Miliary TB

• Influenza 

• Parainfluenza 

• Adenovirus 

Viral Pneumonia 

• Respiratory syncytial virus 

– Children 

• Cytomegalovirus, Herpes 

– Immunocompromised

Viral Pneumonia Micro

RSV Cytopathic Effect

• Atypical pneumonia 

– Walking pneumonia 

Mycoplasma 

• Interstitial pneumonia, bronchopneumonia 

• Often asymptomatic 

• Cold agglutinins present in 50% of cases 

– Anti-I 

–IgM

Fungal Pneumonia 

• Aspergillus niger 

• Pneumocystis carinii 

• Histoplasma capsulatum

Aspergillus niger 

• Colonization of abscess cavity 

• Colonization of tuberculoma 

• Invasive aspergillosis 

– Immunocompromised 

•AIDS 

• Transplants 

– Associated with renal transplant recipients

Aspergilloma Gross

Aspergillus Fungus Ball

Aspergillus Micro 

• Vessel tropic fungus 

• “Holy-water sprinkler”

Aspergillus Micro

Pneumocystis carinii 

• AIDS defining illness 

– Opportunistic fungus 

• bronchoalveolar lavage, biopsy 

• Most common pneumonia in AIDS 

patients, 

– CD4 < 200 

– protein-calorie malnutrition 

• Causes diffuse or patchy pneumonia 

• Little fungi on GMS

P. carinii

Pulmonary Abscess 

• Causes 

– Sino bronchial infections 

– Dental sepsis 

– Obstruction 

– Bronchiectasis 

– Aspiration 

• Alcoholism 

• Coma 

• Drugs 

• Debilitation 

– 10% of cases are associated with underlying carcinoma 

• Aspiration induced abscesses more common on right side 

– Right middle, right lower lobes 

– Right sided bronchus straight shot 

• Cough, fever, copious foul-smelling sputum, chest pain,

Pulmonary Abscess Gross

Aspiration Pneumonia

Pulmonary Abscess 

Necrotizing infection with tissue destruction

Pleuritis

Consequences of Abscesses 

• Empyema 

• Hemothorax 

• Sepsis 

• Adhesions

Diseases of the Lung and Respiratory Tract Part

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