Lung Reviewer Pathology

The Lung- Reviewer Pathology- Dr. Gamboa Justine Villanueva

1. exchange of gases between inspired air and blood- cardinal function of the lung 2. bronchus – bronchiole terminal bronchiole- acinus (respiratory bronchiole, alveolar duct, alveolar sac) 3. pseudostratified, tall, columnar ciliated epithelial cells- lines the lungs 4. type II pneumocyte- secretes surfactant 5. cuboidal- type I pneumocytes 6. flattened- type II pneumocytes 7. trachea to terminal bronchioles- conducting portion of the respiratory system 8. Pores of Kohn- perforations in the alveolar walls which permits passage of bacteria or exudates between adjacent alveoli 9. Lung cancer- most common malignancy 10. Bronchitis and pneumonia- infections 11. Pulmonary hypoplasia- defective development of both lungs where 1 may be more affected than the other resulting to decreased weight, volume and acini disproportional to body weight and AOG 12.Foregut cysts- arise from abnormal detachment of primitive foregut and most often located in the hilum or middle mediastinum 13. Pulmonary sequestrations- refer to the presence of a discrete mass of lung tissue without normal connection to the airways system 14. Extralobar or intralobar- 2 types of pulmonary sequestrations 15. Extralobar- external to the lung, may be located anywhere in the thorax or Mediastinum 16. Intralobar- within the lung, usually in older children associated with recurrent local infections or brochiectasis. 17. Atelectasis- refers either to incomplete expansion of lungs or collapse of previously inflated lung producing areas of relatively airless pulmonary parenchyma 18. Acquired atelectasis in adults may be divided to: a. Resorption atelectasis- consequence of complete obstruction of an airway leading to resorption of oxygen trapped in dependent alveoli, without impairment of blood flow through affected alveolar walls. Mediastinum shifts towards the affected lung. BA, chronic bronchitis, bronchiectasis. b. Compression atelectasis- results whenever the pleural cavity is partially or completely filled by fluid exudates, tumor, blood or air. Pneumothorax or tension c. Contraction atelectasis- occurs when local or generalized fibrotic changes in the lung or pleura prevent full expansion. Irreversible. 19. Pulmonary Edema- can result from hemodynamic disturbances 20. Increase hydrostatic pressure- most common hemodynamic pulmonary edema; occurs in left sided heart failure. a. Presence of alveolar microhemorrhages & hemosiderin-laden macrophages (“heart failure” cells) b. In long-standing pulmonary congestion, fibrosis & thickening of alveolar walls-lungs become firm & brown (brown induration) 21.Edema caused by Microvascular Injury: a. Injury to the capillaries of the alveolar septa b. Remains localized in pneumonia c. If diffuse, can contribute to Acute Respiratory Distress Syndrome 22.Acute Lung Injury (ALI) a. Noncardiogenic pulmonary edema b. Char by abrupt onset of significant hypoxemia & diffuse pulmonary infiltrates in the absence of cardiac failure c. well-recognized complication of diverse conditions, including both direct injuries to lungs & systemic disorders 23. Acute Respiratory Distress syndrome- also refers to acute lung injury 24. Diffuse alveolar damage (DAD)- Histologic manifestation of both ARDS and ALI 25. Morphology of DAD

The Lung- Reviewer Pathology- Dr. Gamboa Justine Villanueva

a. Congestion, interstitial & intra-alveolar damage, inflammation, fibrin deposition & diffuse alveolar damage b. Alveolar walls-lined w/ waxy hyaline membranes c. 26. Endothelial injury-triggers formation of microthrombi (add insult to ischemic injury)in DAD 27. Lung injury-caused by an imbalance of pro- & anti-inflammatory mediators a. Nuclear factor κB (NF- κB)- a transcription factor in favor of a proinflammatory state b. Activation of neutrophils-bind to ligands on act endothelial cells/become “stiff” & less deformable getting trapped in capillary beds c. Dysregulation of coagulation system-dec protein C; inc thrombin 28.Resolution of DAD requires: a. Resorption of exudates b. removal of dead cells & their replacement by new endothelium & alveolar epith cells 29.Clinical course of DAD a. Profound dyspnea & tachypnea b. followed by increasing cyanosis & hypoxemia, respiratory failure c. appearance of diffuse bilateral infiltrates on radiographic examination d. Fxnal abns not evenly distributed throughout the lungs 30. Acute Interstitial Pneumonia- A clinicopathologic term used to describe widespread ALI asso w/ rapidly progressive clinical course that is of unknown etiology, Sometimes referred to as idiopathic ALI-DAD, uncommon, no sex predilection, mean age is 50. 31. Obstructive diseases (airway diseases)- Char by an increase in resistance to airflow due to partial/complete obstruction at any level, from trachea & larger bronchi to terminal & respiratory bronchioles. Decreased maximal airflow rates during forced expiration (measured by forced expiratory vol at 1 sec) 32.Examples of Obstructive diseases a. Chronic bronchitis b. Bronchiectasis c. Emphysema d. Asthma 33. Restrictive diseases- Characterized by reduced expansion of lung parenchyma & decreased total lung capacity; Reduced total lung capacity; N/reduced expiratory flow rate 34.Occurs in 2 general conditions: a. Chest wall d/os-poliomyelitis, severe obesity b. Chronic interstitial & infiltrative diseases-pneumoconiosis; interstitial fibrosis of unknown et. 35.Emphysema & Chronic Bronchitis- grouped together, Overlapping features of damage at both the acinar & bronchial level 36.cigarette smoking- Common extrinsic trigger of emphysema and chronic bronchitis: 37. EMPHYSEMA- Condition of the lung char by irreversible enlargement of airspaces distal to the terminal bronchiole, accompanied by destruction of their walls w/out obvious fibrosis 38. Centriacinar (Centrilobular) Emphysema- central/proximal parts of acini (respiratory bronchioles) are affected, distal alveoli spared; Constitute >95% of all cases; Affects upper zones 39.Panacinar (Panlobular) Emphysema- Acini are uniformly enlarged frm respiratory bronchiole to terminal blind alveoli; “pan” refers to whole acinus; Asso w/ α1-antitrypsin (α1-AT) def ; Affects lower zones 40.Distal Acinar (Paraseptal) Emphysema- Proximal portion of acinus is Normal; distal part is predominantly involved. Multiple, continuous, enlarged airspaces frm 2cm cystlike structures

The Lung- Reviewer Pathology- Dr. Gamboa Justine Villanueva

41.Airspace Enlargement w/ Fibrosis (Irregular Emphysema)- Acinus is irregularly involved; almost invariably asso w/ scarring, Most common; asymptomatic 42.Pathogenesis of Emphysema: a. mild chronic inflammation throughout the airways, parenchyma & pulmonary vasculature b. Most plausible hypothesis to account for the destruction of alveolar wallsprotease-antiprotease mechanism, aided & abetted by imbalance of oxidants & antioxidants 43.Oxidant-antioxidant imbalance-perpetuated by smoking; contain reactive oxygen species; inactivate functional α1-antitrypsin 44. Morphology of Emphysema a. Voluminous lungs b. Abnormally large alveoli separated by thin septa w/ only focal centriacinar fibrosis c. Large pores of Kohn d. Destroyed alveolar walls e. Large abnormal air spaces & possibly blebs/bullae (compressed bronchioles & vasculature) 45.Clinical course of Emphysema a. Dyspnea-1st symptom b. Weight loss-common c. Expiratory airflow limitation (measured by spirometry)-key to diagnosis d. Pink puffers-over ventilate & remain well oxygenated e. Death: 1. respiratory acidosis & coma, 2. right-sided heart failure 3. massive collapse 46.Treatment for Emphysema a. Bronchodilators b. Steroids c. Bullectomy d. lung vol reduction surgery & lung transplantation e. substitution tx w/ α1-AT (being evaluated) 47. Compensatory Hyperinflation (Emphysema)- Pertains to dilation of alveoli but w/ no destruction of septal walls; in response to loss of lung substance 48.Obstructive Overinflation- Lung expands because of trapped air 49.Causes of Obstructive Overinflation a. obstn by a tumor/FB b. congenital lobar inflation (hypoplasia of cartilage, asso cardiac/lung abn) 50. Bullous Emphysema- Large subpleural blebs/bullae (spaces >1cm in diameter in the distended state) 51.Interstitial Emphysema- Entrance of air into ct stroma of lung, mediastinum, subcutaneous tissue, Usually due to alveolar tears-caused by coughing+bronchiolar obstruction 52.Chronic Bronchitis- Defined clinically as persistent cough w/ sputum production for at least 3 mo in at least 2 consecutive years, in the absence of any other identifiable cause 53.When Chronic Bronchitis is persistent it may lead to: a. COPD b. Cor pulmonale & heart failure c. Cause atypical metaplasia & dysplasia 54. long standing irritation by inhaled substance- Primary initiating factor 55.hypersecretion of mucus in large airways asso w/ submucosal glands hypertrophy- earliest feature of chronic bronchitis 56. marked inc in goblet cells of small airways (small bronchi & bronchioles)- if persistent bronchitis

The Lung- Reviewer Pathology- Dr. Gamboa Justine Villanueva

57.Morphology of Chronic Bronchitis: a. Hyperemia, swelling & edema of mucous membranes w/ mucopurulent secretions 58.Histologic: a. chronic inflammation (lymph) & enlargement of mucus-secreting glands (mucus gland hyperplasia) b. Can be assesses by Reid index-N is 0.4 (ratio of thickness of the mucous gland layer to thickness of wall bet epith & cartilage) 59. bronchiolitis obliterans- severe cases of chronic bronchitis 60.Clinical features of Chronic Bronchitis: a. Persistent productive cough-cardinal symptom of chronic bronchitis b. w/ passage of time-hypercapnia, hypoxemia & mild cyanosis (“blue bloaters”) c. Longstanding severe condition-may lead to cor pulmonale w/ cardiac failure & death (superimposed by acute infxn) 61. Asthma- Chronic inflam d/o of the airways that causes recurrent episodes of wheezing, breathlessness, chest tightness & cough, particularly at night/early morning 62. Symptoms: a. Variable bronchoconstriction b. Airflow limitation 63. Hallmarks of the asthma a. increase airway responsiveness to a variety of stimuli resulting in episodic bronchoconstriction, inflam of bronchial walls & inc mucus secretion 64. Status asthmaticus-a state of unremitting attacks w/c is fatal; Significant inc in the Western world in the past 4 decades 65. Atopic Asthma- Evidence of allergen sensitization; pt w/ hx of allergic rhinitis, eczema; type I IgE-mediated hypersensitivity reaction, Diagnosed thru positive family hx, skin test (immediate wheal & flare rxn), 66. serum radioallergosorbent tests (RAST)-identify presence of IgE specific for a panel of allergens in atopic asthma 67. Non-Atopic Asthma- w/out evidence of allergen sensitization 68.Common triggers of non atopic asthma: a. respiratory viruses(rhinovirus,ec) b. Virus-induced inflam of respiratory mucosa-lowers threshold of subepithelial vagal receptors to irritants (hyperirritability of the bronchial tree) 69. Drug-Induced Asthma- Aspirin-sensitive asthma-uncommon; occurs in those w/ recurrent rhinitis & nasal polyps; sensitive also to other NSAIDs; inhibit cyclooxygenase pathway, elaboration of leukotrienes 70. Occupational Asthma- Stimulated by fumes (plastics), organic & chemical dusts (wood), gases & other chemicals, type I rxns, direct liberation of bronchoconstrictor subst & hypersensitivity responses of unknown origin 71. Major etiologic factors (atopy): genetic predisposition to type I hypersensitivity & exposure to envtl triggers (poorly understood) 72.Inheritance-strong TH2 rxn in asthma 73.Late-phase reaction in asthma- Consists largely of inflam w/ recruitment of WBCs (eos, neuts & more T cells)+epith cells-produce mediators (eotaxin-potent chemoattractant & activator of eos; mbp-causes epith damage & airway obstn) 74.Agents present at scene of crime a. histamine (potent bronchoconstrictor); b. prostaglandin D2 (bronchoconstriction & vasodilation); c. platelet-activating factor (aggregation of plt & release of histamine & serotonin) 75.Suspects for whom specific antagonists/inhibitors are not available: a. cytokines (eg IL-1); b. chemokines (eg eotaxin); c. neuropeptides; d. nitric oxide;

The Lung- Reviewer Pathology- Dr. Gamboa Justine Villanueva

e. bradykinin; f. endothelins 76.Genes on chromosome 5q- Genetics of Asthma; onnection w/ IgE regulation & mast cell & eos growth & diff; ex. IL-13-strong asso w/ asthma; TT genotype of CD14 (monocyte receptor w/c encodes for endotoxin) 77.ADAM-33- Belongs to subfamily of metalloproteinases rel to MMPs (eg collagenases); accelerate prolif of bronchial smooth muscle cells & fibroblasts-bronchial hyperreactivity & subepithelial fibrosis 78.β-adrenergic receptor gene- Asso w/ airway hyper-responsiveness & response to βagonist stimulation 79.IL-4 receptor gene- Asso w/ atopy, elevated total serum IgE & asthma 80.Mammalian chitinase family- w/ enzymatic activity-contributes to TH2 stimulation; w/out enzymatic act (YKL-40)-correlate w/ severity of asthma 81.Morphology of Asthma a. Lungs-overdistended (due to overinflation) & small areas of atelectasis b. Mucus plugs-contains whorls of shed epith (Curschmann spirals) c. Numerous eos & Charcot-Leyden crystals (collections of crystalloids-galectin-10) d. “airway remodelling” 82.Clinical Features of Asthma: a. Classic-lasts up to several hrs b. Status asthmaticus-persists for days to wks; may result to cyanosis/death c. Clinical dx aided by: i. Demonstration of inc airflow obstrn; ii. Difficulty w/ exhalation (prolonged, wheeze) iii. Elevated eos ct; Eos, Curschmann spirals & Charcot laden crystals iv. 50% of childhood asthma remits during teens, return in adulthood 83. Bronchiectasis- A disorder characterized by permanent dilation of bronchi & bronchioles caused by destruction of muscle & elastic tissue, resulting frm/or asso w/ chronic necrotizing infxns; a. dev in asso w/: i. Congenital/hereditary conditions (incl cystic fibrosis, intralobar sequestration of lung) ii. Postinfectious conditions incl necrotizing pneumonia (by bact, virus, fungi) 84. Etiology & Pathogenesis of Bronchiectasis: a. Major asso conditions: obstructions and infections b. cystic fibrosis-defect in mucociliary action 85. Acute bronchopulmonary aspergillosis- Condition that results from a hypersensitivity reaction to fungus (Aspergillus fumigatus) a. High serum IgE levels, serum antibodies to Aspergillus, intense airway inflam w/ eos & formation of mucus plugs b. Lead to proximal bronchiectasis & fibrotic lung disease 86. Morphology a. Affects lower lobes bilaterally; vertical air passages; most severe in more distal bronchi & bronchioles b. Dilated airways (sometimes up to 4x N) c. Dilated bronchi appear as cysts filled w/ mucopurulent secretions 87.Histological findings: a. intense acute & chronic inflammatory exudation; necrotizing ulceration; pseudostratification of columnar cells/squamous metaplasia; fibrosis b. Mixed flora can be cultured: staph, strep, pneumococci, enteric org, Aspergillus 88. Clinical Course a. Severe, persistent cough; b. expectoration of foul-smelling, bloody sputum; c. dyspnea; d. orthopnea in severe cases;

The Lung- Reviewer Pathology- Dr. Gamboa Justine Villanueva

e. life-threatening hemoptysis f. Complications: obstructive respiratory insufficiency; Cor pulmonale, brain abscess g. Improved outcome w/ current tx w/ Antibiotics & physical therapy 89. Chronic Diffuse Interstitial (Restrictive) Diseases- A heterogenous grp of d/os char predominantly by inflammation & fibrosis of the pulmonary ct, principally the most peripheral & delicate interstitium in alveolar walls; Most-Unknown cause & pathogenesis; Account for about 15% of noninfectious diseases seen by pulmonary physicians 90. Classic physiologic features- Reductions in carbon monoxide diffusing capacity, lung vol & complianc 91. Chest X-ray- bilateral infiltrative lesions in the form of small nodules, irreg lines/ground glass shadows 92.Complications of Restrictive Disease: a. Secondary pulmonary HPN b. Right-sided heart failure w/ cor pulmonale c. Scarring & gross destruction of the lung (end-stage lung or honeycomb lung) 93.Idiopathic Pulmonary Fibrosis (IPF)- Refers to a clinicopathologic syn w/ characteristic radiologic, pathologic & clinical features, Cryptogenic fibrosing alveolitis 94.Hx pattern of fibrosis: usual interstitial pneumonia (UIP) 95.Abnormal epithelial repair-gives rise to exuberant fibroblast/myofibroblastic prolif (“fibroblastic foci”) in IPF 96.TGF-β1- driver of the process (fibrogenic & released frm type I alveolar epith cells) 97.Morphology of IPF a. Cobblestoned pleural surfaces (retraction of scars along interlobular septa) b. Firm, rubbery white areas (fibrosis) on cut surface at lower lobe, in subpleural regions c. Patchy interstitial fibrosis-hallmark d. Mild to mod inflam in fibotic areas e. Foci of squamous metaplasia & sm hypertrophy 98.Honeycomb fibrosis- Destruction of alveolar architecture & formation of cystic spaces caused by dense fibrosis, lined by hyperplastic type II pneumocytes 99.Clinical Course of IPF a. Begins insidiously w/ increasing dyspnea on exertion & dry cough b. 40-70 yo; hypoxemia, cyanosis & clubbing (late in the dis) c. Tx: steroids, cyclophosphamide, azathioprine; lung transplantation-current definitive tx d. Mean survival-≤3yrs 100. Nonspecific Interstitial Pneumonia (NSIP)- Grp of pts w/ diffuse interstitial lung dis of unknown etiology whose lung biopsies fail to show diagnostic features of any of the other well-char interstitial dis, Has distinct radiologic & hgix features; much better prognosis than do those w/ UIP 101. Morphology of NSIP: a. On the basis of histology, divided into: b. 1. Cellular pattern-consist primarily of chronic interstitial inflam (lymph, plasma cells) in a uniform/patchy distribution c. 2. Fibrosing pattern-diffuse/patchy interstitial fibrosis d. Absent fibroblastic foci & honeycombing 102. Clinical Course of NSIP a. Dyspnea & cough of several months duration b. 46-55yo; cellular pattern-younger & w/ better prognosis 103. Cryptogenic Organizing Pneumonia- Synonymous w/ bronchiolitis obliterans organizing pneumonia, A clinicopathologic syn of unknown etiology, Cough & dyspnea; subpleural/peribronchial patchy areas of airspace consolidation (xray) 104. Histologic (Cryptogenic Organizing Pneumonia)

The Lung- Reviewer Pathology- Dr. Gamboa Justine Villanueva

a. presence of polypoid plugs of loose organizing ct (Masson bodies) w/in alveolar ducts, alveoli & bronchioles b. N lung architecture; no interstitial fibrosis/honeycomb lung c. May recover spontaneously/tx: steroids for ≥6mo 105. Impt to recognize that organizing pneumonia w/ intra-alveolar fibrosis-is seen in response to infxns/inflammatory injury (viral & bact pneumonia, inhaled toxins) 106. Pulmonary Involvement in Connective Tissue Disease- NSIP, UIP, vasc sclerosis, organizing pneumonia & bronchiolitis 107. Pneumoconiosis- Originally coined to describe non-neoplastic lung reaction to inhalation of mineral dusts encountered in the workplace, Now includes disease induced by org & inorganic particulates & chemical fumes & vapors 108. Air pollution-increased morbidity &mortality rates in populations 109. Pathogenesis of Pneumoconiosis a. Dev depends on: i. Amt of dust retained in lung & airways ii. Size, shape & buoyancy of particles iii. Particle solubility & physicochemical reactivity iv. Possible additional effects of other irritants v. 1-5μm in diameter-most dangerous particles; may reach terminal small airways & air sacs & settle in lining; macrophages b. Smaller particles-more likely to appear in pulmonary fluids & reach toxic levels rapidly depending on solubility; acute lung injury c. Larger particles-resist dissolution; persist in lung parenchyma for years; fibrosing collagenous pneumoconiosis 110. Coal Workers’ Pneumoconiosis a. Spectrum of lung findings i. Asymptomatic anthracosis ii. Simple CWP w/ little to no pulmonary dysfxn iii. Complicated CWP/progressive massive fibrosis (PMF) iv. Incompletely understood pathogenesis 111. Anthracosis-most innocuous coal-induced pulmonary lesion in coal miners, urban dwellers & tobacco smokers 112. Simple Coal Workers Pneumoconiosis a. Char by coal macules-1-2mm; b. consists of carbon-laden macrophages; c. Larger coal nodules-contains small amts of collagen fibers d. Affects upper lobes & zones; adj to resp bron; centrilobular emphysema 113. Complicated CWP a. Intensely blackened scars >2cm up to 10 cm; multiple b. Dense Collagen & pigment c. Necrotic center (local ischemia) 114. Silicosis a. Lung dis caused by inhalation of crystalline silicon dioxide (silica) b. Currently the most prevalent chronic occupational dis in the world c. Presents after decades of exposure; slowly progressing, nodular, fibrosing pneumoconiosis d. Acute silicosis (lipoproteinaceous mater) 115. Clinical Course of Silicosis: a. Cxr-fine nodularity in upper zones of lung; pulmonary fxns-N/mod affected b. Progressive dis c. Asso w/ inc susceptibility to TB d. Asso w/ lung CA-contentious 116. Asbestos-a family of crystalline hydrated silicates that form fibers 117. Occupational exposure is linked to: a. Localized fibrous plaques/rarely, diffuse pleural fibrosis

The Lung- Reviewer Pathology- Dr. Gamboa Justine Villanueva

b. Pleural effusions c. Parenchymal interstitial fibrosis (asbestosis) d. Lung CA e. Mesotheliomas f. Laryngeal & other extrapulmonary neoplasms like colon CA 118. Increased incidence of asbestos-rel CA in family members of asbestos workers-alerted the general public to its potential hazard 119. Pathogenesis of Asbestos: 2 distinct geometric forms: a. Serpentine chrysotile chemical forms-most of the asbestos used; more flexible, curled structure impacted at upper respiratory passages & removed by mucociliary elevator; if trapped, leached frm tissues (soluble) b. Amphiboles-more pathogenic (mesotheliomas); straight & stiff-delivered deeper into lungs; penetrate epith cells & reach interstitium c. Both forms-fibrogenic; asso w/ high incidence of asbestos-related dis d. Occurrence-depends on interaction of inhaled fibers w/ lung macrophages & other parenchymal cells e. Eventually lead to generalized interstitial pulmonary inflammation & interstitial fibrosis 120. Morphology of Asbestos Related Chuchu a. Diffuse interstitial fibrosis w/ asbestos bodies b. Golden brown, fusiform/beaded rods w/ a translucent center & asbestos fibers coated w/ an iron-containing proteinaceous material c. Ferruginous bodies d. Other inorg particulates coated w/ iron-protein complexes 121. Pleural plaques- Most common manifestation of asbestos related chuchu; well circ plaques of dense collagen 122. Develop most frequently on anterior & posterolateral aspects of the parietal pleura & overlying the domes of the diaphragm, Associated w/ lung CA (5 fold inc for asbestos workers) & mesotheliomas (pleural & peritoneal; 2-17/million; 1000 fold greater risk) 123. Clinical Course of Asbestos a. Clinical findings similar to those caused by other diffuse interstitial lung dis b. Dyspnea; cough w/ sputum prod c. Appear 10-20 yrs after exposure d. Cxr-irregular linear densities in lower lobes e. May remain static/progress to respiratory failure, cor pulmonale & death f. w/ CA-grim prognosis 124. Drug-Induced Lung Diseases- Can cause acute & chronic alt in respiratory structure & fxn, interstitial fibrosis, bronchiolitis obliterans & eosinophilic pneumonia a. Bleomycin-pulmonary damage & fibrosis; b. Amiodarone-significant pneumonitis 125. Radiation pneumonitis-well known complication of therapeutic radiation of thoracic tumors (lung, breast, esophagus) 126. Acute radiation pneumonitis-1-6mo after; 10-20% of patients; fever, dyspnea 127. Chronic radiation pneumonitis (pulmonary fibrosis)-long term effect; consequence of repair of injured endothelial & epith cells 128. Sarcoidosis- Systemic dis of unknown cause char by noncaseating granulomas in tissues & organs 129. In 90% of cases-bilateral hilar lymphadenopathy/lung involvement, Histologic diagnosis made by exclusion (others: mycobacterial & fungal infxns), Higher in women;10x higher in Blacks 130. Morphology of Sarcoidosis: a. Noncaseating granulomas b. Epithelioid cells, Langhans/FB giant cells; Schaumann bodies (laminated concretions of calcium & proteins);

The Lung- Reviewer Pathology- Dr. Gamboa Justine Villanueva

c. Asteroid bodies (stellate inclusions in giant cells) d. Lungs-common sites of involvement; 1-2 cm, usually not visible grossly e. LN-involved in almost all cases; hilar & mediastinal nodes; enlarged, discrete 131. Clinical Course of Sarcodisos: a. Insidious onset of respiratory abn (shortness of breath, cough)/constitutional s&sxs (fever, fatigue) b. Bilateral hilar adenopathy, cutaneuous lesions, eye involvement, splenomegaly, hepatomegaly c. Unpredictable course: 65-70%-minimal/no residual manifestations; d. 20%-permanent loss of lung fxn/visual impairment; 10-15%-die of cardiac/CNS/lung damage 132. Hypersensitivity Pneumonitis- Spectrum of immunologically mediated, predominantly interstitial lung d/os caused by intense, often prolonged exposure to Agents, 133. “allergic alveolitis”-abn sensitivity/heightened reactivity to Ag involving the alveoli 134. Farmer’s lung disease- Exposure to dusts generated frm humid warm hay containing spore 135. Pigeon breeder’s lung (bird fancier’s dis)- Proteins frm serum, excreta/feathers of birds 136. Humidifier/air-conditioner lung- Thermophilic bacteria in heated water reservoirs 137. Morphology of Hypersensitivity Pneumonitis a. Centered on bronchioles i. Interstitial pneumonitis (lymph, plasma cells, histiocytes) ii. Noncaseating granulomas iii. Interstitial fibrosis, honeycombing & obliterative bronchiolitis 138. Clinical Features (Varied): a. Acute-fever, dyspnea, cough; diffuse & nodular infiltrates in cxr; appear 4-6 hrs after exposure b. Chronic-continued exposure; progressive respiratory failure, dyspnea & cyanosis; dec in total lung capacity