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
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
Pulmonary Hypertension 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
Pulmonary Hypertension 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 Pulmonary Hypertension 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%
Pulmonary Infections Bacterial 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
Miliary TB Not Military TB Looks like lung is shot through with millet seeds Progressive spread in compromised individuals
Miliary TB
Viral Pneumonia Influenza Parainfluenza Adenovirus Respiratory syncytial virus Children Cytomegalovirus, Herpes Immunocompromised
Viral Pneumonia Micro
RSV Cytopathic Effect
Mycoplasma Atypical pneumonia Walking pneumonia 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