Term
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Definition
Lung inflammation due to infection
Lobar - think pneumococcus
Broncopneumonia - think S. aureus, Klebsiella
Commonly just call them acute bronchopneumonias |
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Term
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Definition
Community Acquired - strep pneumoniae
Nosicomial or Necrotizing - staph, gram - (pseudomonas, klebsiella)
Acquired from direct contact, inhalation, aspiration
Pathology - consolidation (to hepatization), alveoli filled with neutrophils
Use cultures to ID bacteria
Clinically - high fever, leukocytosis with neutrophilia, opacities on CXR
Stages: red hepatization -> gray hepatization -> resolution (return to normal architechture)
Rarely see necrosis instead of resolution |
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Term
| Abnormal Bacterial Pneumonias |
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Definition
Legionella - gram - rod that's difficult to stain (use silver)
Bacillus anthracis - acute pneumonia and hemorrhage
Mycoplasma pneumoniae - walking pneumonia (X-ray is worse than the patient), may see high titer of anti-I cold agglutins (hemolytic anemia) |
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Term
| Complications of Bacterial Pneumonia |
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Definition
Necrosis (dead cells), Abscess (necrotic tissue + neutrophils), Scar (fibrosis forming a nodule), Pleuritis (chest pain on inspiration; neutrophilic exudate in pleural space), Empyema (neutrophils and fibrin in pleural space - may need to be peeled off lung surface), Bacteremia (disseminated bacterial infection), Organization (Neutrophils in alveoli replaced with fibroblast plugs/Masson bodies), Bronchiectasis (permanently dilated bronchi due to infection + fibrosis; can be due to CF or Kartagener syndrome; see evidence of inflammation in walls)
-CF: thick mucous causes broncial obstruction + recurrent infection = bronchiectasis
-Kartagener Syndrome: immotile cilia , also associated with situs inversus/dextrocardia |
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Term
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Definition
Second leading cause of pneumonia for adults, leading cause for children
Can cause atypical/walking pneumonia (see "interstitial" radiologic appearance), lymphocytosis
Influenza (dx with serology) - diffuse alveolar damage (hyaline membranes)
CMV (dx with culture) - interstitial
Cytopathic changes - RSV (dx with biopsy), CMV, Herpes (dx with culture)
No cytopathic change - Influenza
CMV - common in immunocompromised (AIDS, transplant pts), see very lg cells with cytoplasmic and nuclear inclusions ("owl eyes") |
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Term
| Bacterial vs. Viral Pneumonia |
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Definition
Bacterial: pathology (neutrophils) in airspaces, productive cough, neutrophilia
Viral: interstitial pathology, non-productive cough, lymphocytosis |
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Term
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Definition
GRANULOMATOUS INFLAMMATION (compact collection of histiocytes, typically is NECROTIZING/CASEATING)
M. tuberculosis - primary and secondary
-primary: ghon focus (necrotizing granuloma forms in lung) + necrotizing granuloma forms in lymph node = ghon complex
-secondary: reactivation or reinfection, see necrotizing granuloma in apex of lung
-TB can heal, progress (to symptomatic), or disseminate (miliary disease)
MAC - AIDS pts
Mycobacteria are acid fast (stain red), can be found in granulomas - culture and PCR to diagnose |
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Term
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Definition
Aspergillus - see hyphae (mold) in tissue; fungus-filled ball
Histoplasma (Ohio and Mississippi River Valleys, St. Lawrence, NY) - yeast in tissue, mold in cultures (dimorphic); granulomatous
Coccidioides (AZ, NM, CA) - dimorphic, granulomatous
Cryptococcus - yeast, granulomatous
Pneumocystis - exclusively in immunocompromised (HIV, transplant, chemo pts), cannot be cultured - ID with lavage, airspaces filled with frothy pink exudate
Blastomyces (rare) - dimorphic, granulomatous
May see acute, febrile illness or healed nodule in immunocompetent pts; unchecked infection in immunosuppressed |
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Term
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Definition
Carcinomas are most common (malignant tumors with epithelial differentiation - either small cell or non-small cell)
Leading cause of cancer deaths
Most important cause is cigarette smoking (other causes: radon, asbestos)
In never-smokers: usually adenocarcinoma, usually in women
Presentation: in pts over 40, hemoptysis, mimics pneumonia, solitary unilateral nodule/mass (metastatic cancer usually shows multiple nodules)
DX ALWAYS REQUIRES CONFIRMATION BY PATHOLOGIST |
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Term
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Definition
Mostly unresectable, treated with chemo, poor prognosis
See scant cytoplasm, no nucleoli, necrosis, high mitotic rate, neuroendocrine features (chromogranin or synaptophysin), nuclear molding; usually large and central (by hilum)
May be metastatic at diagnosis
PATIENTS ARE ALWAYS SMOKERS
May be associated with paraneoplastic syndrome (SIADH, Cushings, Lambert-Eaton Myasthenia gravis) |
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Term
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Definition
Central (by hilum), lots of necrosis (cavitary), MOSTLY IN SMOKERS
May see a paraneoplastic syndrome (hypercalcemia - PTH-related peptide)
Cells make keratin and form intracellular bridges
Necrosis and high mitotic rate |
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Term
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Definition
Tends to be peripheral
Most common type of lung cancer and most common for women (also seen in people with no hx of smoking)
Excellent prognosis for small, noninvasive cancers
Cells make mucin and/or glands
Necrosis less common, still high mitotic rate
Noninvasive (bronchoalveolar) form: spreads along alveolar septa but does NOT invade interstitium |
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Term
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Definition
Non-small cell; lacks differentiating features
Probably represents poorly differentiated squamous cell or adenocarcinoma |
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Term
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Definition
Move through lymphatics to liver, bones, brain, adrenals (or other sites)
Pancoast tumor: arises in lung apices -> invades nerves and soft tissue -> sympathetic nerve plexus involvement = Horner's Syndrome
Staging (how far has tumor spread): TNM - tumor, lymph node metastases, distant metastases
STAGE IS MOST IMPORTANT DETERMINANT OF OUTCOME
Grade: how much does tumor resemble normal structures? done by pathologists. poorly differentiated is worst.(stage trumps grade as prognostic indicator)
Tumors that begin elsewhere often move to lungs:
Colon, Breast, Kidney, sarcoma, melanoma, etc |
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Term
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Definition
Depends on stage
Stage 1 = good, stage 4 = worst
Types:
Small cell - worst
Bronchoalveolar - best
Distant metastases decrease survival
Overall, 15% still alive after 5 yrs |
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Term
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Definition
Uncommon, neuroendocrine tumor (most don't secrete any hormones though; chromogranin and synaptophysin positive) in younger age group
Carcinoid Syndrome: flushing, cramps, diarrhea caused by serotonin secretion by tumor - mostly from ileum tumors
Grow within bronchus and cause obstruction, granular nuclear chromatin (salt and pepper appearance), low mitotic activity, no necrosis
Less aggressive - 90% 5 yr survival |
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Term
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Definition
Uncommon; usually inflammatory or infectious
Chondroid hamartoma - caused by haphazard growth of normal tissues - cartilage, fat, benign spindle cells, may be calcified
Calcifications = benign |
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Term
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Definition
Uncommon; arises in pleura and spreads along outside of lung (no masses, typically)
Suspect with unilateral pleural effusions in elderly
STRONGLY ASSOCIATED WITH ASBESTOS EXPOSURE!
No cure, poor prognosis, 100% mortality
See thickened pleura, epithelial/spindle-shaped malignant cells, stain positive with calretinin |
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Term
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Definition
Rare; arises from thymic epithelium and forms mass in thymus
Associated with myasthenia gravis
Mediastinal mass, cytokeratin-positive, epithelial/spindle-shaped tumor cells, many admixed lymphocytes |
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Term
| Restrictive vs. Obstructive Lung Disease |
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Definition
Restrictive: stiff, hard-to-expand lungs; PFTs: decreased TLC, FVC
Example - Interstitial Lung Disease (Restrictive PFTs = Abnormal Interstitium)
Obstructive: airflow compromised; PFTs: reduced FEV1:FVC
Example - Asthma, COPD (Emphysema + Chronic Bronchitis) |
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Term
| Interstitial Lung Disease (General) |
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Definition
On exam: dyspnea, crackles, cough
Labs: Restrictive PFTs (low TLC and FVC)
CXR: diffuse, bilteral infiltrates
Worst case: progression to honeycomb lung (end stage, scarred, distorted, dilated airspaces with bronchial, not alveolar, epithelium; may contain mucous) |
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Term
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Definition
Causes Interstitial Lung Disease
Non-necrotizing granulomas in lungs (distributed along lymphatics), mediastinal lymph nodes, liver, spleen, eyes, skin
Abnormal response to an unknown antigen (etiology unknown)
May see inclusions (asteroid or schaumann bodies), mostly asymptomatic in young adults
Labs: increased ACE, +Kveim test, hypercalcemia, increased CD4/CD ratio
CXR: bilateral, symmetric lymph node involvment or bilateral lung infiltrates/nodules
Rx: Corticosteriods, many clear up on their own |
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Term
| Hypersensitivity Pneumonia |
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Definition
Cause of Interstitial Lung Disease
Abnormal inflammatory response of lung to inhaled antigens -> Bird Fancier's Lung (avian proteins in feathers), Farmer's Lung (moldy hay bacteria)
Can resolve spontaneously when removed from environment
Pathology: Lymphocytes (not eosinophils), interstitial chronic inflammation, giant cells, non-necrotizing granulomas
Acute: Type III Hypersensitivity Rxn - fever and dyspnea soon after exposure
Chronic: Type IV Rxn - insidious onset
CXR: ground glass opacities, bilateral infiltrates (like other ILDs)
Rx: Remove pt from exposure, corticosteriods |
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Term
| Pulmonary Langerhans Cell Histiocytosis (PLCH) |
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Definition
Proliferation of Langerhans cells (dendritic APCs with birbeck granules and irregular nuclei) in the lung -> cells proliferate in response to cigarette smoke
See: nodular collections of langerhans cells, some eosinophils, respiratory/smoker's bronchiolitis (accumulation of pigment-filled macrophages within bronchioles and alveoli due to cigarette smoke - in ALL smokers)
Usually in young adult smokers, found incidentally; mild dyspnea, cough, lots of tiny nodules with cystic change
Rx: Stop Smoking (may resolve with cessation, or may become honeycomb lung) |
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Term
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Definition
| Fibrosis or chronic inflammation in interstitium/alveolar septum; can be idiopathic |
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Term
| Usual Interstitial Pneumonia (UIP) |
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Definition
If idiopathic, it's called IPF; most causes of UIP turn out to be IPF
ALL CASES OF IPF MUST HAVE UIP
Can also be caused by Rheumatoid Arthritis, Scleroderma, Asbestosis; need repeated episodes of lung injury
Pathology: interstitial fibrosis (patchy) alternating with scarring and honeycomb change and normal lung; see old fibrosis (collagen) and new fibrosis (fibroblasts) - fibroblast focus (ongoing fibrosis sites, aggregates of fibroblasts in septa)
Pts usually 50-60 or older (both sexes), dyspnea and cough, unresponsive to therapy
CXR: bilateral infiltrates, honeycombing
Rx: none - may need lung transplant (poor prognosis, most die within 3 yrs) |
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Term
| Desquamative Interstitial Pneumonia (DIP) |
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Definition
Chronic disease caused by smoking
Extensive respiratory bronchiolitis, mild interstitial fibrosis
Better prognosis than UIP |
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Term
| Acute Interstitial Pneumonia (AIP) |
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Definition
Acute lung disease - diffuse alveolar damage (DAD) of unknown cause
See interstitial thickening due to DAD
Poor prognosis (as for DAD) |
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Term
| Non-Specific Interstitial Pneumonia (NSIP) |
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Definition
Chronic lung disease, idiopathic or secondary to collagen vascular disease or hypersensitivity pneumonia
Uniform, interstitial fibrosis without scarring or honeycomb change
Better prognosis than UIP |
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Term
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Definition
Abnormal accumulation of fluid in intersititum and lung airspaces - can be cardiogenic or noncardiogenic
Cardiogenic (i.e. CHF):
heavy, dark red lungs that exude fluid
alveoli filled with homogeneous pink fluid |
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Term
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Definition
VERY sick pts - severe hypoxemia requiring mechanical ventilation, non-cardiogenic, bilateral diffuse infiltrates, high mortality
many potential causes
Pathology: DAD
Clinical: ARDS |
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Term
| Diffuse Alveolar Damage (DAD) |
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Definition
Underlying pathology in ARDS cases -> manifestation of acute lung injury
Many potential causes: infection (viral - influenza, parainfluenza, RSV, SARS, adenovirus; pneumocystis in immunocompromised), chemotherapy (bleomycin), radiation, shock, sepsis, gastric acid secretions, AIP
Usually no clue as to etiology from pathology
2 Stages (overlap): Acute (1st week - hyaline membranes - see thick pink lines along septa), Organizing (1-2 weeks - fibroblast proliferation) -> can get honeycomb lung after 4-6 weeks
Hyaline membranes: plasma from leaky capillaries + dead cell debris
Pathogenesis: capillary endothelial injury + alveolar lining injury (differs from cardiogenic, where increases hydrostatic forces cause edema) |
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Term
| Bronchiolitis Obliterans Organizing Pneumonia (BOOP) |
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Definition
AKA Organizing Pneumonia
Response to acute lung injury - filling of small bronchioles and alveoli by proliferating fibroblasts (Masson Bodies)
Primary abnormality is in airspaces
Seen with:
1. Pneumonia that heals abnormally
2. Lung injury at the edge of other processes (granulomas, abscesses, tumors)
3. Viral infection, drugs, collagen vascular disease
4. Idiopathic/Cryptogenic: flu-like illness of unknown cause, has a good response to steroids
Can occur with DAD (though DAD is more acute and more severe) |
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Term
| Pulmonary Alveolar Proteinosis (PAP) |
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Definition
Alveolar spaces fill with surfactant-like material caused by poor clearance of intra-alveolar material by macrophages (have autoantibodies to GM-CSF)
See bilateral infiltrates (like pulmonary edema) - CXR findings may be out of proportion to clinical symptoms
Dx: biopsy; see amorphous, granular eosinophilic staining within alveolar spaces with normal interstitium
Rx: whole lung lavage, GM-CSF -> good prognosis |
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Term
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Definition
Rare disease with anti-glomerular basement membrane antibodies
Get pulmonary hemorrhage + renal failure; present with hemoptysis, renal failure
See bilateral infiltrates
Course is often fulminant, high mortality
Lung: blood in alveoli, normal interstitium, linear immunofluorescence staining for IgG and complement
Kidney: crescentic glomerulonephritis, similar IF findings |
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Term
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Definition
Systemic necrotizing granulomatous disease + necrotizing vasculitis, involves lung in most cases
Triad: Upper respiratory tract (ENT), Lung, Kidney (can involve lung only)
Acute, febrile illness with cough, CP, hemoptysis
Labs: c-ANCA (antineutrophil cytoplasmic antibodies)
CXR: nodular densities
Good prognosis with cytotoxic therapy (cyclophosphamide) + steroids -> disease is uniformly fatal without treatment |
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Term
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Definition
Occupational lung disease caused by inhalation of dust - several types: simple (radiologic multiple small lesions), complicated (see "bat wings" - progressive massive fibrosis)
ex: Coal Worker's Pneunoconiosis (Black Lung dz), Silicosis, Asbestosis |
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Term
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Definition
Caused by excessive inhalation of silicon dioxide/crystalline silica
Nodular, fibrotic disease (nodules in lungs and other organs) - UPPER LOBE predomniance
Course: asymptomatic -> becomes acute with heavier exposure (sandblasting) -> can get alveolar proteinosis and/or interstitial fibrosis
Have an increased susceptibility to TB |
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Term
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Definition
Asbestos = fibrous magnesium silicate mineral (chrysotile, amosite, crocidolite and tremolite), used in insulation, shiyards, cement, textiles; particles are tiny (micrometers) and easily respirable - not visible with LM but asbestos bodies (beaded, barbell shaped) are visible, esp with iron stain
Asbestosis: interstitial pulmonary fibrosis + asbestos bodies; restrictive disease with LOWER LOBE predominance, latency 15-25yrs (can resemble UIP)
Pleural Plaques: dense, fibrous, acellular deposits on parietal pleura, diaphragm; may become calcified (latency 30yrs); not malignant - a marker of asbestos exposure
Lung Cancer: increased risk for all types with asbestos exposure, synergism with cigarette smoking, latency 20yrs
Mesothelioma: rare cancer of pleural or peritoneal mesothelium (seen more frequently with asbestos exposure) - NOT linked to smoking, uniformly fatal (usually w/in 1 yr), mimics adenocarcinoma |
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Term
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Definition
Lung injury do to inhalation of talc
Can be associated with asbestos related disease |
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Term
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Definition
ex: Silo Filler's Lung, Bronchiolitis obliterans
Get small airway and alveolar damage; can get pulmonary edema |
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Term
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Definition
Strongly resembles sarcoidosis (non-caseating granulomas)
A kind of hypersensitivity rxn to Be salts (exposure in aerospace, automotive industries) |
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Term
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Definition
Hypersensitivity rxn to cobalt in cemented tungsten carbide tool manufacture/ grinding
Produces Giant Cell Interstitial Pneumonia |
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