1. 2. 3. 4. 5. 6. Pathology 15: The Lung Why do aspirated foreign materials (vomit, blood, foreign bodies) tend to lodge in right lung more than left? Diff b/t bronchiole and bronchi? What is acinus (3parts)? What is a lobule? a. because it is more vertical and more directly in line w/ the trachea b. bronchi have cartilage in walls and submucosal glands; bronchioles don't c. alveolar sacs, alveolar ducts, and respiratory bronchiole (resp unit) d. cluster of 3-5 terminal bronchioles w/ appended acini What is the microscopic structure of the alveolar walls (layers)? What function (s) of type II pneumocyte? What are pores of Kohn? Most common malig in women and lethal visceral-M/F? a. capillary endothelium, basement membrane, interstitial space, alveolar epithelium (type I pneumocytes (95%) and type II (5%), alveolar macrophages (in epithelial), and surfactant b. responsible for synthesis of surfactant and repair of alveolar epithelium (by giving rise to new type I pneumocytes) c. perforations in alveolar walls that llow movement of exudate and bacteria d. Lung cancer (even more than breast) What is cause of pulmonary hypoplasia? of Foregut cysts? What type of foregut cyst is most common? What is pulmonary sequestration and what are 2 types? a. caused by compression of developing lung ie from oligohydramnions or congen diaphragmatic hernia b. caused by abnormal detachment of primitive foregut; bronchogenic most common c. presence of lung tissue w/o normal connection to airway system: extra lobar (in thorax or mediastinum) and intralobar (assoc w/ recurrent infection or bronchiectasis) What is atelectasis? 3 kinds, their causes, position of mediastinum, and reversibility? a. incomplete expansion of lungs (neonatal) or collapse of prev inflated lung b. resorption (obstruction)- caused by mucus plugs or exudates w/ asthma, chronic bronchitis, bronchiectasis, aspiration of foreign body; mediastinum-TOWARD problem; reversible c. compression- pleural cavity filled w/ fluid, tumor, blood, air (pneumothorax); mediastinum- AWAY from affected lung; reversible d. contraction- from local/gen fibrotic changes in lung preventing expansion; not reverseable 2 causes of pulmonary edema? What is most common cause of hemodynamic? Where does fluid tend to accumulate and what 2 histologic findings may occur with it? a. hemodynamic changes (increased hydrostatic pressure) and increased capillary permeability (usually from injury from infection) b. left-sided heart failure most common; fluid accum in base of lungs (more hydrostatic pres) c. "heart failure" cells (hemosiderin-laden alveolar macrophages) and 'brown induration' (brown fibrous thickening of lung) What is an acute lung injury (ALI)? What called when severe? What’s that associated with? If causal infectious agent can't be identified, what classified as? a. abrupt onset of hypoxemia and diffuse pulmonary infiltrate in the absence of cardiac failure b. Acute respiratory distress syndrome (ARDS) if severe; assoc w/ Sepsis; c. if etiologic assoc absent--> acute interstitial pneumonia (AIP) 7. Macroscopic appearance of lung in ALI? Characteristic microscopic findings (2)? What is cause of pathogenesis in ARDS though to be and what is role of immune system? a. lungs are heavy, firm, red, and boggy; also exhibit congestion b. diffuse alveolar damage and waxy hyaline membrane (from mixed fibrin rich edema fluid and lipid/cytoplasmic remnants of necrotic epithelial cells) c. in ARDS the integrity of alveolar capillary membrane barrier (epithelium and/or endothelium) is compromised; though by imbalance of pro-inflamm. and antiinflamm d. 30 min post insult, IL-8 recruits neutrophils that adhere endothelium (enhanced by TNF and IL-8) and then become stiff and trapped in lungs, then release products that damage 8. What is the clinical presentation of person w/ acute lung injury? What is presentation of functional abnormalities? a. dyspnea and tachypnea, increased cyanosis and hypoxemia, resp failure, diffuse bilateral infiltrates on radiograph, poor response to O2 therapy (mismatch), stiff lung if no resolve b. functional abnorm not evenly distributed: regions of infiltration, of consolidation, of collapse, and normal regions--> causes ventilation-perfusion mismatch (40% mortality) 9. 2 categories of noninfectious diffuse pulmonary diseases? What characterized by? Causes? Results on pulmonary function tests? a. obstructive- increased resistance to airflow from part/full obstruction; asthma, chronic bronchitis, bronchiectasis, emphysema, bronchiolitis; dec max airflow on forced expiration b. restrictive- reduced expansion of lung parenchyma and dec total lung capacity; chest wall disorders (poliomyelitis, obesity, kyphoscoliosis), chronic interstitial/infiltrative diseases; have reduced total lung capacity, compliance, and expiratory flow norm or reduced proportionally [phys: FEV1/FVC increased] 10. Why are emphysema and chronic bronchitis often clinically grouped together? Anatomic site involved? Why is asthma distinguished separately? a. the occur at similar levels (acinar-emph; bronchus-chronic bronc), are triggered by smoking, and small airway disease is a component of both- together make COPD b. asthma is has reversible component (bronchospasm); COPD irriversible 11. What is emphysema? 4 types? Which assoc w/ obstruction? Characteristics of each type (where occur, assoc w/, etc)? Which is asymptomatic? a. irreversible enlargement of airspaces distal to terminal bronchiole accompanied by destruction of their walls without obvious fibrosis b. Centriacinar(centrilobular)- most common type to cause obstruction; involves Proximal part of acini(resp bronchiole); lesions more common in apical segments; assoc w/ smoking c. Panacinar(panlobular)- causes obstruction; uniform enlargement of entire acini; lesions more common in lower zone of lungs; assoc w/ alpha1-antitrypsin deficiency d. Distal acinar(paraseptal)- prox acinis okay, distal part involved; cyst-like enlarged airspaces occuring near areas of fibrosis; severe in upper lung; assoc. w/spon pneumothorax e. Irregular (airspace enlargement w/ fibrosis)- due to scaring; asymptomatic 12. What leads to the destructive process in emphysema? What is most common normal alpha1-antitrysin allele?How does smoking lead to pathogenisis in emphysema (2)? a. destruction from protease-antiprotease imbalance and imbalance of oxidantsantioxidants b. 99.9% have an M allele (ppl w/ homozygous Z allele tend to get panacinar) c. Smoke causes accumulation of neutrophils and macrophates in alveoli (nicotine is a chemoattract), neutrophils/macrophages release proteases, macrophage elastases not inhibited by anti-trypsinase (cause damage) i. tobaco causes increased ROS and neutrophils cause oxidative damage to alpha-1 antitrypsinase (fxnal deficiency)--> neutrophil proteases not inactvated either! 13. What are 4 contributors to airflow obstruction in emphysema? a. goblet cell metaplasia (mucus plugs), loss of elastic recoil (from elastases), inflammatory infiltrate in walls of bronchioles, and thickening of walls from smooth m. hypertrophy 14. What is morphologic apperance of emphysema? What is clinical presentation? Key to diagnosis? 3 main causes of death in these ppl? Cause-obstructive overinflation? Interstitial emphysema? a. voluminous lungs (upper 2/3 more severely affected) w/ abnormally large alveoli that have lost attachment to outer wall of small airways b. dyspnea (first), weightloss, 'barrel-chested, dyspneic, hunched over, pursed lips, hyperinflammation' --> Pink puffer c. 1) respiratory acidosis=> coma, 2) cor pulmonale (R. sided heart failure), and 3)pneumothorax=> massive lung collapse d. air trapped in lung by obstruction from tumor or foreign object (air can get in, not out), or conginital lobar overinflation in infants e. air in connective stroma due to alveolar tear (common), chest wound, or irritant gas inhlation 15. What defines chronic bronchitis? 3 possible sequalae? What is initating factor, earliest feature, and late feature? a. persistent cough w/ sputum production for at least 3 months in last 2yrs w/o identifyable cause b. progression to COPD, cor pulmonale, dysplasia leading to cancerous transformation c. long standing irritant (smoke; also dust, silica); hypersecretion of mucus in large airways and hypertrophy of submucosal glands earliest feaure d. later- marked increase in goblet cells of small bronchi and bronchioles=xs mucus 16. What is role of infection in chronic bronchitis? What are morphologic features of chronic bronchitis? Clinical presentation? a. secondary role (doesn't initiate, but may prolongue) b. bronchi and trachea have lymphocytic infiltrate and enlargment of mucous glands (measured by Reid index); bronchioles obliterated by fibrosis (broniolitis obliterans) i. emphysema=>metaplasia; bronchitis=>hyperplasia of goblet cells c. presistent productive cough, eventual dyspnea and COPD-hypercapnia, hypoxemia, mild cyanosis ("blue bloater") 17. What is asthma? What are 3 hallmarks of the disease? 2 main different forms and causes? 2 other? a. chronic inflammatory disorder of airways causing recurrent episodes of weezing, breathelessness, chest tightness, cough (esp night/early morn) from bronchoconstriction b. increased airway responsiveness to stimuli, episodic bronchoconstriciton, increased mucus c. atopic (most common; type 1 IgE-mediated hypersensitivity; allergic; positive skin test); non-atopic (neg skin test; hyperirritable bronchial tree often assoc w/ viral infection) d. Drug induced (aspirin- less lipoxygenase=bronchoconstrict) and occupational 18. What are major etiologic factors in atopic asthma? type of immune response that occurs? What happens to the airways over time? a. genetic predisposition to type I hypersensitivity (elevated IgE) and exposure to environmental triggers leading to development of TH2 response b. TH2 releases IL-4=> B cell IgE production, IL-5=> eosinophils, and IL-13=> mucus production; IgEs coat mast cells and subsequent antigen exposure leads to crosslinked IgE and degranulation=> early rxn (vasodilation, bronchoconstrict); late-rxn eotaxin and chemokines (recruit eosinophils, neutrophils, Tcells)=> eosinophil MBP=> tissue damage c. "airway remodeling"- hypertrophy/hyperplasia of bronch smooth m., epithelial injury, increased vascularity, increased gland hypertrophy, deposition of subep collagen 19. What chromosome has susceptibility loci for asthma? What other genetic polymorphisms implicated in asthma? Most striking macroscopic findings? Histologic? a. chromosme 5q (related to IgE regulation and mast cell and eosinophil growth/diff) b. class II HLA alleles (reason IgEs bind to only some things), ADAM-33, B2 adrenergic receptor gene, IL-4 receptor gene, chitinases c. macro- occlusion of bronchi/bronchioles by thick mucus plugs and lungs overdistended w/ small areas of atelectasis d. micro- Curschmann spirals (whorls of shed epithelium w/ mucus), CharcotLeyden crystals(eosinophils bound to protein), and airway remodeling 20. What is bronchiectasis characterized by? What congenital conditions may it develop in assoc with? Infections it may develop w/? Other possible causes? a. PERMANENT dilation of bronchi/bronchioles caused by destruction of muscle and elastic tissue, resulting from or assoc w/ chronic necrotizing infections (need: infection+obstruct) b. cystic fibrosis, intralobar sequestration of lung, primary ciliary dyskinesia/Kartagener c. necrotizing pneumonia caused by bacteria (M. tuberculosis, S. aureus, H. infleunza, Pseundomonas), viruses (HIV, influenza, adenovirus), and fungi (aspergillus) d. bronchial obstrution (tumor, foreign body, mucus impaction) and other conditions: RA, SLE, IBD, and post-transplant 21. What leads to bronchiectasis in cystic fibrosis? What is Kartagener syndrome? Where does brochiectasis affect lungs most? Morphologic appearance? Clinical presentation? a. mutated CFTR channel leads to viscus mucus that is susceptible to infections; recurrent infections destroy smooth m., elastic tissue, and cause dilation/fibrosis b. occurs in 50% of ppl affected with primary ciliary dyskinesia (absent/shortened dynein arms); signs are bronchiectasis, sinusitis, situs inversus or partial laterization abnorm, sperm dysmotility c. infections tend to affect lower lobes bilaterally, esp in more vertical air passages (TB is an exception to this trend) d. airways dilated up to 4x normal; intense acute/chronic inflammatory exudate w/ extensive areas of necrotizing ulceration, squamous metaplasia, and eventual fibrosis e. severe persistent cough, expectoration of foul-smelling, sometimes bloody sputum (worse after positional change), dyspnea and orthopnea 22. What are chronic restrictive diseases characterized by? Symptoms of ppl w/ these? Lab and radiographic findings? What are late stage restrictive diseases referred to as? a. inflammation and fibrosis of pulmonary connective tissue b. dyspnea, tachypnea, end-inspiratory crackles, eventual cyanosis c. reduced CO diffusion capacity, lung volume, and compliance; radiograph: bilateral infiltrative lesions in form of small nodules, irreg lines, or ground-glass shadows d. end-stage lung or honey-comb lung 23. 5 categories of restrictive lung diseases? What is idiopathic pulmonary fibrosis? Currently believed cause? What is the driver of this process and why? What is Caveolin-1? a. fibrosing diseases, granulomatous diseases, pulmonary eosinophilia, smokingrelated interstitial diseases, and pulmonary alveolar proteinosis b. IPF = crytogenic fibrosing alveolitis; caused by repeated cycles of epithelial activation/injury by some unidentified agent (usually via Th2 repsonse) c. TGF-β1 drives process: it negatively regulates caveolin-1 as well as telomerase, which causes epithelial apoptosis and repair (abnormal forming fibroblastic foci); d. an endogenous inhibitor of pulmonary fibrosis and TGF-β1 (caveolin-1 decreased in IPF) 24. What is gross appearance of lungs in IPF? Where most affected? Microscopic hallmark and earliest lesion? What does dense fibrosis eventually lead to? Pulm artery changes? Outlook? a. pleural surface is cobblestoned from scar retractions; cut surface is firm, white, rubbery b. lower-lobe distributed in subpleural regions and interlobular septa c. Hallmark- patchy interstitial fibrosis; earliest lesion= fibroblastic foci (prolif fibroblasts) d. fibrosis eventually leads to alveolar destruction and formation of cystic spaces lined by type II pneumocytes= honeycomb fibrosis e. pulmonary artery changes from HTN- intimal fibrosis and medial thickness f. BAD!! mean survival is only 3 yrs and lung transplant only therapy 25. What histologic pattern of fibrosis must be found for diagnosis of IPF? What is nonspecific interstitial pneumonia? Why is nonspecific interstitial pneumonia (NSIP) important to recognize? What morphologic features are not present? a. pattern referred to as Usual Interstitial Pneumonia (UIP, essentially described above) b. diffuse interstitial lung disease (fibrosing) of unknown etiology whose biopsies fail to show diagnostic features of any other well-characterized interstitial diseases c. important to recognize b/c MUCH better prognosis than UIP (pattern of IPF) d. can have cellular and fibrosing patterns; IMPORTANT: fibroblastic foci and honeycombing are absent in NSIP! 26. What is another name for cryptogenic organizing pneumonia? Radiograph findings? Histologic findings? How treated and what is it usually caused by? a. bronciolitis obliterans organizing pneumonia b. subpleural or peribronchial patchy areas on radiograph c. presene of polypoid plugs of loose connective tissue (Masson bodies) in alveolar ducts, alveoli, and bronchioles (fibrosis all same age); NO interstitial fibrosis or honeycomb lung d. can accompany inflammation or infection 27. What systemic diseases can cause pulmonary involvment? Most common patterns? What is found in RA, in Scleroderma, in SLE? a. SLE, scleroderma, rheumatoid arthritis, deratomyositis-polymyositis, mixed connective tissue disease b. NSIP, UIP (as in IPF), vascular sclerosis, organizing pneumonia, and bronchiolitis i. Keyword: fibrosis c. RA- chronic pleuritis, diffuse interstitial fibrosis (NSIP or UIP), intrapulmonary rheumatoid nodules, and pulmonary HTN d. scleroderma- diffuse interstitial fibrosis (generally NSIP) e. SLE- patchy and transient infiltrates, occasional lupus pneumonitis 28. What does the term pneumoconioses (fibrosing disease) mean? What extrinsic factors does development of one of these diseases depend on (4)? a. non-neoplastic lung reaction to inhalation of organic/inorganic particulates, vapors, fumes b. the amount of dust retained by lung and airways, the size/shape/buoyancy of particles, particle solubility/reactivity, and additional effects from other irritants 29. What 3 factors determine quantity of dust is retained in lungs? Most dangerous particles? How does size of particles affect disease presentation? What inhaled mineral effect worsened by smoking? a. dust concentration in air, duration of exposure, and effectiveness of clearance mech b. particles from 1-5 um diameter b/c reach terminal airways and settle in linings! c. smaller particles- soluble so tend to accum to toxic levels in pulm fluids more quickly= acute lung injury; larger one resist dissolve-chronic fibrosing collagenous pneumoconioses d. asbestos 30. Major culprit in Coal Workers Pneumoconiosis (CWP)? 3 forms of lung findings? Morphologic findings in each? What does coal dust increase incidence of (independent of smoking)? a. carbon dust b. asymptomatic anthracosis- pulm lesion from inhaled carbon pigment c. simple CWP -coal macules(1-2cm containing coal laden macrophages) and coal nodules (larger containing coal laden macrophages and collagen); Upper lobe involvement, can cause centrilolobular emphysema in time d. Complicated CWP- progressive massive fibrosis w/ intensly blackened scars >2 cm made of dense collagen and pigment (req many years to develop) e. generally benign but does increase incidence of chronic bronchitis and emphysema 31. What is most prevalent chronic occupational disease in the world? 2 professions affected? What is causitive agent and how does it cause fibrosis? a. Silicosis- inhalation of crystalline silicon dioxide (silica); sandblasters and mine workers b. quartz (a crystalline silica); silica causes macrophage activation and release of mediators 32. What are early morphologic findings of silicosis in lung? Later? Radiographic findings in lymph nodes and lung? What histologic findings? Infection susceptible to? Carcinogenic? a. tiny blackened nodule in upper zone b. progress to hard collagenous scars (may undergo cavitation or softening) c. nodes- eggshell calcification (radioleucent middle; opaque edge); lung-fine nodularity in upper zones on radiograph d. lesion histo-concentric layers of hyalinized collagen surrounded by dense collagen capsule; nodules reveal 'birefringent' silica particles w/ polarized light e. tuberculosis yes; carcinogenic maybe 33. What 6 things is exposure to asbestos associated with? What are 2 geometric forms and characteristics of each? Where does inital asbestos injury tend to occur? a. localized fibrous plaques, pleural effusions, parenchymal interstitial fibrosis (asbestosis), lung carcinoma, mesothelioma, laryngeal/colon neoplasms b. serpentine (less pathogenic b/c more flexible and soluble; dont get as deep in lung) and amphibole (more pathogenic b/c stiff and less soluble; invade deeper lungs & penetrate) c. at bifurcations of small airways/ducts (macrophages try to clear and instead are activated to release fibrogenic mediators leading to chronic deposition) 34. What are the morphologic features of asbestosis in lung? How differentiated from UIP? Part of lung most often inolved? Most common manifestation of asbestos and location? a. diffuse pulmonary interstitial fibrosis with presence of asbestos bodies (golden brown, fusiform/beaded rods w/ translucent center coated by iron material (from macrophages)) b. has fibrosis and progression to honeycomb of UIP; asbestos bodies only difference c. Lower lobes most involved (contrast to other forms of pneumoconiosis) d. pleural plaques- plaques of dense collagen most freq on anterior or postlat of parietal pleura and over domes of diaphragm (NO asbestos bodies) 35. Which cancer risks are assoc w/ concommittant asbestosis and smoking? What do chest x-rays of asbestosis reveal? Possible disease progression? a. lung carcinoma risk is further increased by smoking; mesothelioma risk doesn’t synergize with cigarette smoke b. x-rays show irregular linear densities particularly in lower lobes w/ honeycomb in advanced; pleural plaques will appear as circumscribed densities c. can progress to respiratory failure, cor pulmonale, and death 36. Which lung tends to be involved in radiation-induced pneumonitis? What is sarcoidosis characterized by? 2 most commonly involved structures? How diagnosed? a. lung within the radiation port b. noncaseating granulomas in many tissues and organs c. bilateral hilar lymphadenopathy or lung involvement (90% cases) d. via exclusion (other fungal and microbial diseases that produce granulomas [like hypersensitivity pneumonitis] ruled out) 37. What immune, genetic, and environmental factors may contribute to sarcoidosis? What are morphologic findings and what tissues involved? a. immune- accumulation of CD4+ cells, increased Th1 cytokines, recruitment of Tcells and macrophages (also demonstrate hypergammaglobinemia and anergy to skin tests like PPD) b. genetic- assoc w/ HLA genotype; environ- possibly infection but not proven c. noncaseating granulomas that may have Schaumann bodies (calcium) and asteroid bodies (stellate inclusions) inside; d. Lungs, lymph nodes (enlarged, calcified), spleen and liver (scattered granulomas), bone marrow (usually phalanges), skin lesions, eyes (iritis, glaucoma, opacity), gland enlargement, muscle weakness 38. Where do lung granulomas tend to occur in sarcoidosis? When do most cases of sarcoidosis come to clinical attention? a. primarily along lymphatics, bronchi, and blood vessels b. when person seeks help for resp abnormality (SOB, chest pain) or constitutional symptoms 39. What is hypersensitivity Pneumonitis (granulomatis)? Why is it important to recognize hypersensitivity pneumonitis early? How different from asthma? What is causal agent in Farmer's, Pigeon breeder's and Humidifer lung? Type of hypersensitivity? a. immunologically mediated lung disorder from exposure to inhaled organic agent b. because you can prevent it from progressing to chronic fibrotic lung disease by removing environmental agent c. hypersensitivity pneuonitis tends to involve alveoli insead of bronchi i. although both involve antigen-antibody complex formation (at least atopic asthma does), HP also requires a longer exposure time than asthma before it occurs; asthma has an immediate hypersensitivity stage d. Farmers- thermophilic actinomycetes; pigeon- serum, excreta, or feathers of bird; humidifier- thermophilic bacteria in heated water reserves e. Type III (evidenced by specific antibodies in serum and complement/immunoglobulins in vessel walls); Some type IV as well (granulomas suggest delayed-type hypersensitivity) 40. 3 characteristic histologic changes in hypersensitivity pneumonitis? What can it progress to? What are different forms of pulmonary eosinophilia? a. interstitial pneumonitis, noncaseating granulomas, and interstitial fibrosis, honeycombing, and obliterative bronchiolitis (in late stages) b. can progress to resp failure, dyspnea, and cyanosis w/ decreased lung capacity/compliance c. acute eosinophilic pneumonia w/ resp failure, simple pulmonary eosinophilia(striking shadows on CT, but benign), Tropical eosinophilia (microfilariae), idiopathic, secondary, chronic diagnosed by exclusion 41. 2 types of smoking-related interstitial diseases? Characterized by? Clinical features? a. Desquamative interstitial pneumonia- large collection of macropages w/ dusty brown pigment (smokers' macrophages); insidious onset of dyspnea and clubbed digits b. Respiratory bronchiolitis-associated interstitial lung disease- smokers' macrophages in first and second order resp bronchioles; more mild dyspnea and cough 42. What radiologic findings characterize pulmonary alveolar proteinosis? Histologic? 3 classes of PAP and cause of each? Morphologic findings? Symptoms and treatment? a. bilateral patchy asymmetric pulmonary calcifications b. accumulation of acellular surfactant in the intra-alveolar and bronchiolar spaces c. Acquired- autoimmune production of anti-GM-CSF antibody (GM-CSF needed to clear surfactant); congenital- mutations needed for surfactant (ABCA3, SP-B, SP-B); secondary-hematopoetic disorders, malignancies, immunodeficiencies d. peculiar homogenous granular precipitate in alveoli making them confluent w/ turbid fluid; stain with PAS and surfactant proteins present; Lungs increased size and weight e. cough w/ gelatinous chunks of sputum, progressive dyspnea, resp insufficiency f. treat w/ whole-lung lavage (wash out); GM-CSF therapy helps some 43. Origin of blood clots in pulmonary artery? Who is at risk? Primary vs secondary risk factors for hypercoagulable state (increased risk of embolus)? What does response to PE depend on (5)? a. emboli from deep veins of legs; b. ppl w/ underlying cardiac disase, cancer, or immobilized (ie after a hip fracture) c. Primary- Factor V Leiden, prothrombin mutations, Antiphospholipid syndrome; secondary- obesity, recent surgery, cancer, oral contraceptive, pregnancy d. extent to which vessel is obstructed, size of occluded vessel(s), number of emboli, status of cardiovascular system, and release of vasoactive factors 44. 2 main pathophysiologic consequences of pulmonary emboli? 2 causes of death from PE? Who tends to get infarcts as a consequence? Location? Appearance? How is PE distinguished from post-mortum clot? a. Most commonly they cause no symptoms! Otherwise, respiratory compromise (non-perfusion) and hemodynamic compromise (pulm HTN) b. sudden death (as w/ saddle embolism) from embolus or acute cor pulmonale c. older ppl w/ already inadequate circulation (heart/lung disease); lower lobes of lungs d. classically hemorrhagic infarct that progresses from red-blue, to red-brown (hemosiderin), to gray-white (fibrous replacement) e. lines of Zahn in pulmonary embolism (from being in flowing blood) 45. What symptoms may someone who survives PE present with? Radiograph findings and lab findings? Sequalae?What is important to note in someone w/ small PE? Prophylaxis? a. severe chest pain, dyspnea, shock, fever, increased serum lactate dehydrogenase b. may look normal or may have wedge-shaped infiltrate; diagnose w/ spiral CT or ventilation perfusion scan c. overtime unresolved emboli lead to: pulm HTN, pulm vasc sclerosis, cor pulmonale d. small emboli frequently precede a large one (30% chance of second) e. early ambulation in post-op, compressive stockings for bedridden, anticoag, IVC filter 46. At what fraction of systemic pressure does pulmonary pressure become pulm htn? 5 similar disorders associated with it? 5 common causes? a. 1/4th systemic; pulmonary arterial HTN, PH w/ left heart disease, PH w/ lung disease, PH from chronic thrombotic/embolic disease, miscellaneos PH b. chronic and restrictive lung disease, congenital/acquired heart defect, recurrent thromboemboli, connective tissue disease (systemic sclerosis), obstructive sleep apnea (fat) 47. What is mutated in familial pulmonary HTN and how does it cause disease? What is cause of pulmonary HTN in secondary forms? a. bone morphogenic protein receptor type 2 (BMPR2); causes apoptosis of smooth m. in vessels, so when 1 allele lost= vascular thickening and HTN b. endotelial cell dysfxn from sheer mechanical injury or from biochemical injury 48. What 3 morphologic features are found in PH regardless of cause? What vessels prominently affected? What is presentation of PH caused by drugs or HIV? Clinical presentation/course? a. medial hypertorphy of muscular and elastic arteries, atheromas of pulmonary artery, and right ventricular hypertrophy b. arterioles and small arteries (40-300um diameter) c. Plexiform lesion- tuft of capillary formations is present producing a network or web d. dyspnea and fatigue progressing to cyanosis, severe resp distress, right ventricular hypertrophy, and death from cor pulmonale 49. 3 pulmonary hemorrhagic syndromes? What is cause of Goodpasture? What is unusual about the population affected? What are morphologic findings and clinical sequalae? a. goodpasture syndrome, idiopathic pulmonary hemosiderosis, vasculitis-assoc hemorrhage (hypersensitivity angiitis, Wegener granulomatosis, SLE) b. autoantibodies against α3 chain of type IV collagen in basement membrane of glomeruli and alveoli c. autoimmune cause that is predominantly in males in 20s (smoking also related) d. Lungs- necrotic hemorrhagic interstitial pneumonitis (red-brown consolidation, focal necrosis of alveolar walls, intra-alveolar hemorrhage); kidney- cresenteric glomerulonephritis; NOTE: linear immunofluorescence in both organs 50. Who does idopathic pulmonary hemosiderosis occur in? What are 2 diagnosticly important features for Wegener Granulomatosis? a. young children b. capillaritis and scattered poorly formed noncaseating granulomas (unlike those of sarcoidosis that are well formed) 51. What is pneumonia? 5 factors that can lower local defences increases risk? 3 important facts to keep in mind when thinking about it? 7 pneumonia syndromes? a. any infection of the lung parenchyma b. loss/suppresion of cough reflex, injury to mucociliary apparatus, accumulation of secretions (in obstructive diseases), interference w/ phagocytic action of macrophages, pulmonary congestion and edema c. one type of pneumonia sometimes predisposes to another, hematogenous spread from one organ to another can occur, patients w/ chronic disease acquire terminal pneu in hospital d. community acquired acute, community acquired atypical, hospital acquired, aspiration, chronic, necrotizing/lung abscess, pneumonia in immunocompromised 52. Most common cause of community-acquired acute pneumonia? How diagnosed? What is most common bacterial cause of acute exacerbations of COPD? Characteristics? other diseases caused? a. Streptococcus pneumoniae (pneumococcus); sputum gram-stain reveals gram +, lancet-shaped diplocci b. Haemophilus influenzae; gram neg bacteria that causes life-threatening acute lower resp infection and meningitis in kids; comm pneumo in adults (3rd most?) c. NOTE: type b H. influenzae is major encapulated problem; has pili, proteases that degrade IgA, factors that disorganize ciliary beating 53. 2nd most common cause of acute exacerbations of COPD? 3 most common causes of otitis media in children? Who generally affected by S. aureus pneumonia? Most freq gram neg pneu? Most frequent hospital-acquired pneu? a. Moraxella catarrhalis b. S. pneumoniae, H. influenzae, M. catarrhalis c. children and adults secondary to viral illness, IV drug abusers d. Klebsiella pneumoniae (esp in malnourished like chronic alcoholics) e. P. aeruginosa 54. Where does legionella pneumophila thrive? Who’s particularly succeptible to this type of community pneumonia? 2 patterns of bacterial pneumonia and type of consolidation in each? a. artificial aquatic environment (water-cooling towers) b. organ transplant recipients c. bronchopneumonia- patchy consolidation of the lung; lobar pneumoniafibrosuppurative consolidation of large portion or entire lobe 55. 4 stages of inflammatory response in lobar pneumonia and morphology of each? Morphology of bronchopneumonia? 3 major complications? Clinical presentation? a. congestion (lung heavy, boggy, red, w/ intra-alveolar fluid and many bacteria), red hepatization (massive exudation w/ neutrophils, redcells, fibrin= red firm airless lung w/ liver consistency); gray hepatization (disintegratin of RBCs to fibrinosuppurative exudate, gray brown); resolution (enzymatic digestion and resorption) b. suppurative, patchy, multilobular, bilateral, basal lesions that are dry, granular, and yellow c. tissue necrosis and abscess formation, empyema(spread to pleural cavity), and bacteremic dissemination (endocarditis, meningitis, supp arthritis) d. abrupt onset of fever, shaking chills, productive cough and occasional hemoptysis 56. What makes an atypical pneumonia atypical? Most common causal organism? What is predominat histologic pattern? Major clinical manifestations? a. = viral or Mycoplasma; only moderate sputum, no physical findings of consolidation, only moderate elevation in whites, and lack of alveolar exudate, architecture not distorted i. TB is a whole other genus b. Mycoplasma pneumoniae (esp children and young adults) (often viral causes too) c. interstitial nature of inflammatory rxn, virtually localized w/in walls of alveoli d. generally mild compared to typicals; fever, headache, muscle aches/pain; can have 2ndary bacterial infection 57. What is structure of influenza virus and how does this result in epidemics and pandemics? Strain of avian influenza of concern? Morphologic presentation of viral resp infections? a. 8 helical ssRNA segments in envelope w/ hemagglutinin and neuramidase on outside b. epidemic- mutation in H or N that allows virus to escape host antibodies (antigenic drift); pandemic- both H and N replaced via recomb w/ RNA segs of other species (antigenic shift) c. H5N1 (usually spread through domestic birds) – H5 allows all tissues to be infected d. mucosal hyperemia and swelling w/ predom lymphocytic infiltrate and mucus oversecrete; can have swelling of vocal chords in laryngotracheobronchitis or bronchiolitis 58. Who is most commonly infected by human metapneumovirus (MPV)? Presentation? What is causal agent of SARS? How first transmitted to humans? Symptoms and diagnosis? a. young children, elderly, and immunocompromised b. severe bronchiolitis and pneumonia that may require hospitalization i. resembles RSV c. an unidentified coronavirus; via wild masked palm civets eaten in China d. dry cough, malaise, fever, progressing to SOB, tachypnea, and 10% die e. diagnosed via detection of the coronavirus by PCR or detection of antibodies to virus (serum, sputum) 59. Who commonly affected by hospital-acquired pneumonia (3)? Most common cause? 2 others? What is most commonly found on culture for aspiratoin pneumonia? sequalae? a. immunosuppressed, on prolongued antibiotics, or have invasive devices (cath, ventilator) b. Most commonly P. aurginosa; also gram neg rods (enterobacteriaceae) and S. aureus (NOT S. pneumoniae) c. more than one organism (aerobes more than anaerobes); death or lung abscess 60. What is a pulmonary abscess? What organisms are most commonly isolated? 3 common anaerobes? Major mechanisms abscess acquired through? = Primary cryptogenic if no other cause a. local suppurative process characterized by necrotic lung tissue b. aerobic and anaerobic streptococci, S. aureus, many gram negative organisms c. those found in oral cavity normally: Bacteroides, fusobacterium, peptococcus d. aspiration of infective material (most common; alcoholic, coma, sinusitis, gingivodental sepsis), from preceding lung infection, septic embolism, neoplasia, trauma, spread from neighboring organs or via hematogenous route 61. Where are abscesses from aspiration most common? From pneumonia? septic? What is cardinal histologic change in all abscesses? What can continual infection lead to? How diagnosed? Complications? a. more common on right and single; from pneumonia tend to be multiple, diffuse, basal; embolic can be any part of lung and multiple b. suppurative destruction of lung parenchyma w/ central area of cavitation c. large, fetid, green-black pool of necrotic debris-gangrene of lung d. diagnosed only by radiology; e. complicated by infection of pleural cavity, hemorrhage, and brain abscess 62. What types of organisms tend to cause chronic pneumonia? 3 features of the fungal causes? Where (geographic) is each fungal cause most frequent? a. those that form granulomas: bacteria (M. tuberculosis) and fungi b. Histoplasmosis, blastomycosis, and coccidiodomycosis: all cause granulomatous disease in lungs, all are thermally dimorphic, and all have specific geographic location c. Histo- by Ohio and Mississippi rivers and Caribbean, [prof. owl teaches History] d. Blasto- central and SE US, [cannon blasts surrounding the Alamo] e. Coccidio- SW and far west US and Mexico (10% get San Joaquin Valley fever) 63. How is histoplasmosis capsulatum aquired (2 sources)? Clinical presentation resembling tuberculosis(4)? Morphologic presentation? How diagnosed? a. from inhalation of dust particles of soil contaminated w/ bird or bat droppings b. self-limited laatent disease, can lead to chronic secondary lung disease involving lung apices, localized lesions in extrapulmonary sites, and wide disseminated immunocompromise c. epitheliod granulomas undergo caseous necrosis; undergo fibrosis to 'tree-bark' lesions d. diagnosed by culture or ID of fungus in tissue lesions 64. 3 clinical forms of Blastomyces dermatitidis infection? What type of granuloma? morphology? Type of immune response to Coccidioides immitis? Morphologic presentation? a. pulmonary blastomycosis, disseminated blastomycosis, and primary cutaneous (rare) b. suppurative granuloma; budding yeast w/ thick, double contoured cell wall, mult nuclei c. delayed-type hypersensitivity; granulomaous lesions similar to histo and macrophages filled w/ nonbudding spherules of endospores 65. What is most common and serious complication in immunocompromised ppl? Commonly causal organisms? Leading cause of morbidity and mortality in HIV? a. pulmonary infiltrate (with or w/o signs of infection) b. bacteria (P. aeruginosa, mycobacteria, Listeria), viruses (CMV, HSV), fungi (P. jiroveci, candida, aspergillus, cryptococcus) c. Pulmonary disease 66. 3 principles to keep in mind when thinking about HIV pulmonary disease? Most common pathogens involved in HIV resp infections? a. resp infections often caused by the "usual" pathogens of resp tract, disease can still have non-infectious etiology (Kaposi sarcoma, lung cancer), CD4 + count defines risk to infections of specific organisms (bacteria if >200, pneumocysitis<200, myco avium<50) b. S. pneumoniae, S. aureus, H. influenzae, and gram neg rods like P. aeruginosa 67. Most common indications for lung transplantation (4)? When must both lungs be replaced? 2 main complications and morphology with each? a. end-stage emphysema, idiopathic pulmonary fibrosis, cystic-fibrosis, and idiopatic/familial arterial hypertension b. bilat if chronic infection present c. Pulmonary infections (generally bacterial in 3-12th month post transplant) and rejection (acute-inflammatory infiltrate around small vessels or airways; chronicbroncholitis obliterans (partial or complete occlusion of small airways by fibrosis)) Tumors 68. Do most smokers get lung cancer? Who has greater susceptibility to carcinogens found in cigarettes? Does it help to quit? a. 10% of smokers get lung cancer (but 90% of all lung carcinomas happen to smokers) b. Women are more susceptible to lung cancer c. Cessation of smoking for 10 years reduces risk, but not to control levels i. risk persists for 30 years 69. Which type of cancer tends to involve the genes 3p, p53, BCL2, C-KIT, and MYCN/MYCL? a. Small cell lung carcinoma has involvement of these genes [small numbers=> small cell] 70. What about the genes p16 INK4a, p53, EGFR, and KRAS? a. These genes are most commonly affected in any non-small cell lung carcinoma 71. What gene is known for causing familial clustering through increased metabolization of procarcinogens? a. The P-450 gene CYP1A1 may increase an individual’s metabolization of cigarette procarcinogens 72. How do characteristics of small cell carcinomas versus non-small cell carcinomas compare? a. Small cell carcinomas are almost always metastatic and have a high initial response to chemotherapy b. Non-small cell carcinomas are the opposite (less often metastatic, less responsive) 73. To which organ is lung cancer most likely to metastasize? a. The adrenal glands are involved in more than half of metastases i. Other possibilities: liver, brain, & bone 74. What is the most common type of lung cancer? Where do they originate? What substances do they express? a. Adenocarcinomas are the most common; b. Adenocarcinomas are usually more peripherally located compared to other carcinomas c. they are usually positive for TTF-1 and mucin 75. What type of cancer is bronchioalveolar carcinoma? What is its key feature? Which subtype, in turn, tends to spread aerogenously? a. Bronchioalveolar carcinoma is a type of adenocarcinoma b. Its key feature is a lepidic growth pattern: it grows along preexisting structures c. Mucinous bronchioalveolar carcinoma tends to spread aerogenously you’ll suffocate 76. How is squamous cell carcinoma histologically identified? a. Squamous cell carcinoma is characterized by keratinization and/or intracellular bridges 77. Which two carcinomas are closely correlated with smoking history? a. Squamous cell and small cell carcinomas almost always occur in smokers 78. Which carcinoma is most likely to ectopically secrete hormones? What carcinoma causes hypercalcemia? Through what intermediates? a. The highly malignant small cell carcinoma was the culprit in our SIADH case b. Exception: Hypercalcemia is usually due to squamous cell carcinoma i. caused by parathyroid hormone, PTH related peptide, prostaglandin E, and some cytokines [think: calcium plating] 79. Which cancer type probably represents squamous/adeno-carcinomas that have become very undifferentiated? What do you call a cancer with combined histology of 2+ types? a. Large cell carcinoma is perhaps just a mix of de-differation b. Combined carcinoma has combined histology 80. How would you stage a cancer that is invading the mediastinum and heart, with ipisilateral hilar or peribronchial nodal involvement? What defines N2? a. This cancer would receive an T4 N1 M0 b. T4 or N3 always = IIIb c. N2+ requires local metastasis to mediastinal or subcarinal lymph nodes 81. How would you stage a cancer of 3-7 cm in size or that involved main stem bronchus, visceral pleura, or lobar atelectasis? [no nodal involvement] a. This describes a T2 N0 M0 cancer b. T2 with nothing else = stage Ib 82. What is the difference between stage IIb and IIIa? a. IIb = T2N1 or T3N0 b. IIIa = T3N1 or T3N2 83. Which neuroendocrine tumor obstructs bronchi and sometimes fans out along the perbronchial tissue as a collar button lesion? What rare syndrome can they produce? What other cancer causes this syndrome? a. Carcinoid tumors—penetrate the bronchial wall to cause obstruction b. Carcinoid syndrome is a rare complication: intermittent attacks of diarrhea, flushing, cyanosis c. Carcinoid syndrome is actually more commonly seen in patients with small cell carcinoma, simply because small cell carcinoma itself is so much more common 84. What miscellaneous tumor tends to produce connective tissue, specifically cartilage, that is visible as a coin lesion on chest films? a. Lung hamartoma 85. What is the growth pattern of metastasis to the lung? a. Multiple discrete nodules “cannonball lesions” scatterred throughout all lobes 86. Asbestos workers are vulnerable to which pleural tumor? How does it look? List some important histology: a. Malignant Mesothelioma b. Spindle and cuboidal cells invade adipose tissue c. Stain features favoring diagnosis: acid mucopolysaccharide; keratin; calretinin, WT-1, cytokeratin 5/6, and D2-40; long microvillia and abundant tonofilaments w/absent microvillous rootlets; lack of epithelial glycoprotein antigens [we have to kare for our asbestos workers] 87. How can you differentaite solitary fibrous tumor from malignant mesothelioma? Where are solitary fibrous tumors located? a. Solitary fibrous tumors are positive for CD34 and keratin-negative b. pleura [Alternate] 88. What is most freq diagnosed cancer in world and most common cause of cancer mortality worldwide? Peak age of incidence? 3 factors in smoking that affect risk of carcinoma? a. Lung cancer; 50-60s b. amount of daily smoking, tendency to inhale, and duration of smoking habit 89. Typical mutation in lung cancer? Environmental factors linked to lung cancer (4)? Genes most linked to small cell lung carcinoma? non-small cell? Type of lung cancer in nonsmokers? a. G:C>T:A mutations in p53 caused by benzo[a]pyrene in smoke b. smoking (cigarettes and cigars(less)), ionizing radiation (ie uranium in miners), asbestos, indoor air polution-radon (esp in miners) c. small cell: C-Kit, MYCN, MYCL, p53, 3p, RB, BCL2; non-small- EGFR, KRAS, p16INK4a d. in non-smoking women- adenocarcinomas w/ EFGR mutations, but no KRAS or p53 90. 3 types of precursor lesions to lung carcinoma? 4 types of lung cancer? Most common in women? 2 groupings based on likelihood metastases and chemo response? Most assoc w/ smoking (2)? a. squamous dysplasia and carcinoma in situ, atypical adenomatous hyperplasia, and diffuse idiopathic pulmonary neuroendocrine cell hyperplasia b. Adenocarcinoma (most common in women and in some studies men), squamous cell carcinoma, small cell carcinoma, large cell carcinoma; NOTE: can have more than 1 c. small cell carcinomas (almost always metastatic, high response to chemo) and non-small cell carcinomas (less often metastatic, less responsive to chemo) d. small cell carcinoma and squamous cell carcionoma 91. Where in lung do tumors tend to arise? Which tend to arise more peripheral/distally? Which carcinoma often preceded by precursors? Appearance of tumors? Where metastasize to? a. in and about the hills; adenocarcinomas can occur more perish/distal b. Squamous cell carcinomas tend to come from precursors c. tumors tend to be gray-white and firm; may have hemorrhage or necrosis d. lymph- tracheal, bronchial, mediatinal nodes; hematog- adrenals (most), liver, brain, bone 92. What type of differentition in adenocarcinoma? Most common cancers of who? What are majority of them positive for? What is morphology for bronchioalveolar form? What precursor? a. gladular; most common cancers of women and non-smokers b. positive for thyroid transcription factor-1 (TTF-1) and 80% have mucin c. pure bronchioalveolar growth pattern that grow along PREEXISTING structures without destruction (lepidic); can be nonmucinous (better) or mucinous (worse prognosis) d. thought to arise from atypical adematous hyperplasia that then progresses to bronchioalveolar carcinoma and can transform into invasive adenocarcinoma 93. Who is sqamous cell carcinoma most commonly found in? Histologic features it is characterized by? Most common mutation? a. men and close assoc w/ smoking history b. presence of keratinization(squamous pearls) and/or intercellular bridges c. highest freq mutation in p53 (others: RB1, p16(INK4a), EGFR, HER-2/NEU) 94. Histologic appearance of small cell carcinomas? What findings on EM? What markers suggest a neuroendocrine origin?Relation to smoke? MOST COMMON assoc ectopic hormone production a. small cells w/ scant cytoplasm, ill-defined cell borders, finely granular nuclear chromatin ('salt and pepper' pattern), abscent nucleoli; high mitotic count and necrosis common b. EM shows dense-core neurosecretory granules; c. markers- chromogranin, synaptophysis, CD57; smoking increases risk! 95. Morphologic findings of large cell carcinoma? What is neuroendocrine variant characterized by? Secondary symptoms/pathology from lung tumors (6)? a. undifferentiated epithelial tumor that lacks cytology of small-cell, gladular, or squamous tumors; cells have large nuclei, prominent nucleoli, and moderate cytoplasm b. variant recognized by organoid nesting, trabecular, rosette-like, and palisading patterns c. partial obstruction (emphysema), complete obstruction (atelectasis), severe suppurative bronchitis or bronchietasis, pulmonary abscess, SVC syndrome, pleuritis/pericarditis 96. Most aggressive lung tumors incurable by surgical means? Major presenting complaints in lung cancer? Which lung tumor does not metastasize? 2 patters w/ slightly better prognosis?Table15-11 a. small cell carcinoma b. cough, weight loss, chest pain, and dyspnea c. bronchioalveolar does not; adenocarcinoma and squamous cell better (local longer) d. NOTE: KRAS mutation assoc w/ worse prognosis regardless of treatment 97. Hormone products that can be elaborated by lung tumors (7)? 2 hormones most secreted predominately by small cell? 1 by squamous cell? What do apical lung tumors cause? a. ADH, ACTH, PTH, PTHrP, Calcitonin, Gonadotropins, Serotonin/bradykinin b. small cell- ADH and ACTH; sqamous- those producing hypercalcemia (PTH, PTHrP) c. Pancost tumors- compress cervical symp plexus causing combo: pain in ulnar nerve distribution and Horner syndrome (ptosis, miosis, anhidrosis) 98. 3 neuroendocrine tumors of lung? What is all pulm neuroendocrine cell hyperplasia secondary to? 2 types of carcinoid tumors and differences? 2 morphologic patterns of growth? Symp carcinoid? a. tumorlets (small, inconsequential), carcinoids, and small/large cell carcinomas b. typical (no mutations in p53, or BCL2 and BAX abnormalities, low mitoses, no necrosis) and atypical (mutations in p53, Bcl2, BAX, more mitoses, necrosis present) c. growth ino lumen of main stem broncus or penetration through bronchial wall to fan out collarbutton lesion;both have microscopic organoid, trabecular, palisading, or rosette look d. intermittent attacks of diarrhea, flushing, cyanosis (syndrome); also cough hemoptysis 99. Apperance of hamarotma on radiography? What is most common tissue in these? Microscopic findings in inflammatory myofibroblastic tumor? 2 tumors most likely to grow into lungs? a. incidental round lesion of radio-opacity (coin lesion); nodule of cartilage most common b. prolif of spindle-shaped fibroblasts, myofibroblasts, lymphocytes, plasma cells c. esophageal carcinomas and mediastinal lymphomas d. NOTE: lung is most common site of metastatic neoplasms (from both blood and lymph) 100. What is most common cause for pathologic involvement of pleura? 2 important primary disorders? 5 causes of pleural effusion? a. mst often it is a secondary complication of some underlying disease b. primary intrapleural bacterial infectins and primary pleural neoplasm (mesothelioma) c. increased hydrostatic pressure (congest <3 fail), increased vascular permeability (pneumonia), decreased osmotic pressure (nephrotic synd), increased intrapleural negative pressure (atelectasis), and decreased lymph drainage (mediastinal carcinomas) 101. Common causes of inflammatory pleuritis? What is empyema and when does it occur? What is hemorrhagic pleruitis caused by? What is most common cause of hydrothorax? Hemo-? chylo? a. inflammatory diseases in lungs (pneumonia, tuberculosis), lung infarcts, lung abscesses, bronchiectasis, and radiation therapy b. purulent yellow-green creamy exudate from bacterial seeding of pleural space (gen from spread of intrapulmonary infection); tends to undergo fibrosis c. caused by hemorrhagic diatheses, rickettsial disease, and neoplastic involvement (sanguinous inflammatory exudate; must diff from hemothorax) d. hydro- clear and straw colored non-inflammatory fluid caused often by heart failure; hemo- most often from ruptured aortic aneurysm, chylo- thoracic duct trauma or obstruct 102. What are pneumothoraxes most commonly associated with (3)? What are 3 forms and their cause a. emphysema, asthma, and tuberculosis b. spontaneous (can complicate lung disease or can be idiopathic from rupture of apical subpleural blebs), traumatic (chest wall injury), tension (defect acts as flap>air trapped in) 103. What is most common cause of pleural tumors? What exudate do these tend to produce? What is microscopic appearance of solitary fibrous tumor? How diff from malig mesothelioma? a. secondary metastatic involvement (often from Breast and Lung) b. tend to cause serous or serosanguineous effusion (often containing neoplastic cells) c. confined; consists of fibrous tissue with whorls of reticulin and collagen fibers and interspersed spindle cells; d. tumor cells are CD34+ and keratin-negative (diff from meso) and no relation to asbestos 104. What causes increased risk of malig mesotheliomas? What doesn't? What is macroscopic appearance of these tumors? 3 microscopic patterns? a. asbestos exposure increases risk; smoking does not (in contrast to lung cancer) b. diffuse pink gelatinous tumor that spreads widely in plerual space (lots effusion) c. Epithelioid (cuboidal, columnar, or flattened cells), sarcomatoid(spindle cells resembling fibrosarcoma), and mixed (has both of other 2) 105. How can epithelioid type of mesothelioma be distinguished from lung adenocarcinoma(5)? What other mesothelioma strongly linked to asbestos? Clinical presentation of mesothelioma? a. meso stains positive for acid mucopolysaccharide, lacks staining for epithelial glycoprotein antigens, stains for perinuclear keratin, stians for calretinin, EM (no lamellar bodies) b. peritoneal mesothelioma highly related c. present with chest pain, dyspnea, and recurrent pleural effusions; metast to hilar nodes