Pulmonary Pathology Flashcards
1
Q
Rhinitis
A
- inflammation of the nasal mucosa
- most common cause is rhinovirus
- common cold (sneezing, congestion, runny nose)
2
Q
Allergic Rhinitis
A
- subtype of rhinitis
- due to a type I hypersensitivity reaction (e.g. pollen)
- inflammatory infiltrate with eosinophils
- associated with asthma and eczema
3
Q
Nasal Polyp
A
- protrusion of edematous, inflamed nasal mucosa
- usually secondary to repeated bouts of rhinitis
- also occurs in CF and aspirin-intolerant asthma
4
Q
Aspirin-Intolerant Asthma
A
- characterized by the triad of asthma, aspirin-induced bronchospasms, and nasal polyps
- seen in 10% of asthmatic adults
5
Q
Angiofibroma
A
- benign tumor of nasal mucosa
- composed of large blood vessels and fibrous tissue
- classically seen in adolescent males
- presents with profuse epistaxis
6
Q
Nasopharyngeal Carcinoma
A
- malignant tumor of nasopharyngeal epithelium
- associated with EBV
- classically seen in African children and Chinese adults
- biopsy usually reveals pleomorphic keratin-positive epithelial cells (poorly differentiated squamous cell carcinoma) in a background of lymphocytes
- often presents with involvement of cervical lymph nodes
7
Q
Acute Epiglottitis
A
- inflammation of the epiglottis
- common cause is H. influenzae type B (esp. non-immunized children)
- high fever, sore throat, drooling with dysphagia, muffled voice, and inspiratory stridor
- risk of airway obstruction
8
Q
Laryngotracheobronchitis (Croup)
A
- inflammation of the upper airway
- parainfluenza virus is most common cause
- hoarse, “barking” cough and inspiratory stridor
9
Q
Vocal Cord Nodule (Singer’s Nodule)
A
- nodule that arises on the true vocal cord
- due to excessive use of vocal cords; usually bilateral
- composed of degenerative (myxoid) connective tissue
- presents with hoarseness
- resolves with resting of voice
10
Q
Laryngeal Papilloma
A
- benign papillary tumor of the vocal cord
- due to HPV 6 and 11
- papillomas are usually single in adults and multiple in children
- presents with hoarseness
11
Q
Laryngeal Carcinoma
A
- squamous cell carcinoma usually arising from the epithelial lining of the vocal cord
- risk factors are alcohol and tobacco
- can rarely arise from a laryngeal papilloma
- presents with hoarseness
- other signs include cough and stridor
12
Q
Pneumonia
A
- infection of the lung parenchyma
- when normal defenses are impaired (impaired cough reflex, damage to mucociliary escalator, or mucus plugging)
- fever and chills, productive cough with yellow-green (pus) or rusty (bloody) sputum, tachypnea, pleuritic CP, dec breath sounds, dullness to percussion, elevated WBC count
- diagnosed with CXR, sputum gram stain and culture, and blood cultures
- 3 patterns on CXR: lobar pneumonia, bronchopneumonia, and interstitial pneumonia
13
Q
Lobar Pneumonia
A
- characterized by consolidation of an entire lung lobe
- usually bacterial (S. pneumoniae (95%); Klebsiella pneumoniae are most common)
- Classic gross phases of lobar pneumonia:
1. congestion (due to congested vessels and edema)
2. red hepatization (due to exudate, neutrophils, and hemorrhage filling the alveolar air spaces, giving the normally spongy lung a solid consistency)
3. gray hepatization (due to degradation of red cells within the exudate
4. resolution
14
Q
Bronchopneumonia
A
- characterized by scattered patchy consolidation centered around bronchioles
- often multifocal and bilateral
- caused by a variety of bacterial organisms
15
Q
Interstitial (Atypical) Pneumonia
A
- characterized by diffuse interstitial infiltrates
- presents with relatively mild upper respiratory sxs (minimal sputum and low fever)
- “atypical” presentation
- caused by bacteria or viruses
16
Q
Aspiration Pneumonia
A
- seen in pts at risk for aspiration (alcoholics and comatose pts)
- most often due to anaerobic bacteria in the oropharynx (e.g. Bacteroides, Fusobacterium, and Peptococcus)
- classically results in a right lower lobe abscess
- anatomically, the right main stem bronchus branches at a less acute angle than the left
17
Q
Primary Tuberculosis (TB)
A
- inhalation of aerosolized Mycobacterium tuberculosis
- primary TB arises with initial exposure
- results in focal, caseating necrosis in the lower lobe of the lung and hilar lymph nodes that undergoes fibrosis and calcification, forming a Ghon complex
18
Q
Secondary TB
A
- arises with reactivation of Mycobacterium tuberculosis
- reactivation is commonly due to AIDS; may also be seen with aging
- occurs at apex of lung (relatively poor lymphatic drainage and high oxygen tension)
- forms cavitary foci of caseous necrosis; may also lead to miliary pulmonary TB or TB bronchopneumonia
- fevers, night sweats, cough with hemoptysis, weight loss
- biopsy reveals caseating granulomas
- AFB stain reveals acid-fast bacilli
- systemic spread often occurs and can involve any tissue; common sites include meninges (meningitis), cervical lymph nodes, kidneys (sterile pyuria), and lumbar vertebrae (Pott disease)
19
Q
Basic Principles of COPD
A
- group of diseases characterized by airway obstruction
- lung does not empty; air trapping
- decreased FVC
- extremely decreased FEV1
- decreased FEV1/FVC ratio
- TLC is usually increased due to air trapping
20
Q
Chronic Bronchitis
A
- chronic productive cough lasting at least 3 months over a minimum of 2 yrs; highly associated with smoking
- hypertrophy of bronchial mucinous glands
- leads to increased thickness of mucus glands relative to bronchial wall thickness
- productive cough due to excessive mucus production
- cyanosis (“blue bloaters”) due to mucus plugs trapping carbon dioxide and increased PaCO2 and dec PaO2
- increased risk of infection and cor pulmonale
21
Q
Emphysema
A
- destruction of alveolar sacs
- loss of elastic recoil and collapse of airways during exhalation results in obstruction and air trapping
- due to imbalance of proteases and antiproteases (excessive inflammation or lack of A1AT leads to destruction of the alveolar air sacs)
- alpha-1 antitrypsin (A1AT) neutralizes proteases
- smoking is most common cause (smoke pollutants lead to inflamm. and protease-mediated damage)
- smoking results in centriacinar emphysema that is most severe in upper lobes
- A1AT deficiency is a rare cause
- disease severity is based on the degree of A1AT deficiency
- dyspnea and cough with minimal sputum
- prolonged expiration with pursed lips (“pink puffer”)
- weight loss
- inc anterior-posterior diameter of chest (“barrel chest”)
- hypoxemia and cor pulmonale are late complications
22
Q
A1AT Deficiency
A
- lack of antiprotease leaves the air sacs vulnerable to protease-mediated damage
- results in panacinar emphysema that is most severe in the lower lobes
- liver cirrhosis may also be present (A1AT def. due to misfolding of the mutated protein; accumulates in the ER of hepatocytes, resulting in liver damage; biopsy reveals pink, PAS-positive globules in hepatocytes)
- PiM is the normal allele
- PiZ is the most common clinically relevant mutation (significantly low levels of A1AT)
- PiMZ heterozygotes are usually azymptomatic with dec circulating levels of A1AT (significant risk for emphysema when smoking exists)
- PiZZ homozygotes are at significant risk for panacinar emphysema and cirrhosis
23
Q
Asthma
A
- reversible airway bronchoconstriction
- most often due to allergic stimuli (atopic asthma)
- presents in childhood; often associated with allergic rhinitis, eczema, and a family history of atopy
- type I hypersensitivity
- clinical features are episodic and related to allergen exposure
- dyspnea and wheezing
- productive cough, classically with spiral-shaped mucus plugs (Curschmann spirals) and Eosinophil-derived crystals (Charcot-Leyden crystals)
- severe, unrelenting attack can result in status asthmaticus and death
- may also arise from nonallergic causes (non-atopic asthma) such as exercise, viral infection, aspirin, and occupational exposures
24
Q
Pathogenesis of Asthma
A
- type I hypersensitivity
- allergens induce Th2 phenotype in CD4+ T cells of genetically susceptible individuals
- Th2 cells secrete IL-4 (mediates class switch to IgE), IL-5 (attracts eosinophils), and IL-10 (stimulates Th2 cells and inhibits Th1)
- reexposure to allergen leads to IgE-mediated activation of mast cells
- release of preformed histamine granules and generation of leukotrienes C4, D4, and E4 lead to bronchoconstriction, inflammation, and edema (early-phase reaction)
- inflammation, especially major basic protein derived from eosinophils, damages cells and perpetuates bronchoconstriction (late-phase reaction)
25
Q
Bronchiectasis
A
- permanent dilation of bronchioles and bronchi
- loss of airway tone results in air trapping
- due to necrotizing inflammation with damage to airway cells
- caused by CF, Kartagener syndrome, tumor or foreign body, necrotizing infection, and allergic bronchopulmonary aspergillosis
- cough, dyspnea, foul-smelling sputum
- complications include hypoxemia with cor pulmonale and secondary (AA) amyloidosis
26
Q
Kartagener Syndrome
A
- inherited defect of the dynein arm, which is necessary for ciliary movement
- associated with sinusitis, infertility (poor motility of sperm), and situs inversus (position of major organs is reversed, e.g. heart is on right side of thorax)
27
Q
Allergic Bronchopulmonary Aspergillosis
A
- hypersensitivity reaction to Aspergillus leads to chronic inflammatory damage
- usually seen in individuals with asthma or CF
28
Q
Basic Principles of Restrictive Diseases
A
- restricted filling of the lungs
- decreased TLC
- decreased FEV1
- extremely decreased FVC
- FEV1:FVC ratio is increased
- most commonly due to interstitial diseases of the lung
- may also arise with chest wall abnormalities (e.g. massive obesity)
29
Q
Idiopathic Pulmonary Fibrosis
A
- fibrosis of lung interstitium
- likely related to cyclical lung injury
- TGF-beta from injured pneumocytes induces fibrosis
- secondary causes of interstitial fibrosis such as drugs (e.g. bleomycin and amiodarone) and radiation therapy
- progressive dyspnea and cough
- fibrosis on lung CT; initially seen in subpleural patches, but eventually results in diffuse fibrosis with end-stage “honeycomb” lung
- treatment: lung transplantation
30
Q
Pneumoconioses
A
- interstitial fibrosis due to occupational exposure
- requires chronic exposure to small particles that are fibrogenic
- alveolar macrophages engulf foreign particles and induce fibrosis
31
Q
Coal Workers’ Pneumoconiosis
A
- type of pneumoconioses
- carbon dust exposure
- massive exposure leads to diffuse fibrosis (“black lung”)
- associated with rheumatoid arthritis (Caplan syndrome)
- mild exposure to carbon (e.g. pollution) results in anthracosis (collections of carbon-laden macrophages); not clinically significant
32
Q
Silicosis
A
- type of pneumoconioses
- silica exposure
- seen in sandblasters and silica miners
- fibrotic nodules in upper lobes of the lung
- increased risk for TB
- silica impairs phagolysosome formation by macrophages
33
Q
Berylliosis
A
- type of pneumoconioses
- beryllium exposure
- seen in beryllium miners and workers in the aerospace industry
- non-caseating granulomas in the lung, hilar lymph nodes, and systemic organs
- increased risk for lung cancer
- very similar to sarcoidosis
34
Q
Asbestosis
A
- type of pneumoconioses
- asbestos fiber exposure
- seen in construction workers, plumbers, and shipyard workers
- fibrosis of lung and pleura (plaques) with increased risk for lung carcinoma and mesothelioma
- lung carcinoma is more common than mesothelioma in exposed individuals
- lesions may contain long, golden-brown fibers with associated iron (asbestos bodies), which confirm exposure to asbestos
35
Q
Sarcoidosis
A
- systemic disease characterized by non-caseating granulomas in multiple organs
- likely due to CD4+ helper T-cell response to an unknown antigen
- granulomas most commonly involve the hilar lymph nodes and lung leading to restrictive lung disease
- characteristic stellate inclusions (“asteroid bodies”) are often seen within giant cells of the granulomas
- other commonly involved tissues include the uvea (uveitis), skin (cutaneous nodules or erythema nodosum), and salivary and lacrimal glands (mimics Sjogren syndrome); almost any tissue can be involved
36
Q
Clinical Features of Sarcoidosis
A
- dyspnea or cough (most common presenting symptom)
- elevated serum ACE
- hypercalcemia (1-alpha hydroxylase activity of epithelioid histiocytes converts vit. D to its active form)
- treatment is steroids; often resolves spontaneously without treatment
37
Q
Hypersensitivity Pneumonitis
A
- granulomatous rxn to inhaled organic antigens (e.g. pigeon breeder’s lung)
- presents with fever, cough, and dyspnea hours after exposure
- resolves with removal of the exposure
- chronic exposure leads to interstitial fibrosis
38
Q
Pulmonary Hypertension (Basic Principles)
A
- high pressure in the pulmonary circuit (mean arterial pressure > 25 mmHg; normal is 10 mmHg)
- characterized by atherosclerosis of the pulmonary trunk, smooth muscle hypertrophy of pulmonary arteries, and intimal fibrosis
- plexiform lesions are seen with severe, long-standing disease
- leads to RVH with eventual cor pulmonale
- presents with exertional dyspnea or right-sided heart failure
- subclassified as primary or secondary based on etiology
39
Q
Primary Pulmonary Hypertension
A
- classically seen in young adult females
- etiology is unknown
- some familial forms are related to inactivating mutations of BMPR2, leading to proliferation of vascular smooth muscle
40
Q
Secondary Pulmonary Hypertension
A
- due to hypoxemia (e.g. COPD and interstitial lung disease) or increased volume in the pulmonary circuit (e.g. congenital heart disease)
- may also arise with recurrent pulmonary embolism
41
Q
Acute Respiratory Distress Syndrome
A
- diffuse damage to the alveolar-capillary interface (diffuse alveolar damage)
- leakage of protein-rich fluid leads to edema that combines with necrotic epithelial cells to form hyaline membranes in alveoli
- secondary to a variety of disease processes including sepsis, infection, shock, trauma, aspiration, pancreatitis, DIC, hypersensitivity rxns, and drugs
- activation of neutrophils induces protease- and free radical-mediated damage of type I and II pneumocytes
- recovery may be complicated by interstitial fibrosis; damage and loss of type II pneumocytes leads to scarring and fibrosis
42
Q
Clinical Features of ARDS
A
- hypoxemia and cyanosis with respiratory distress - due to thickened diffusion barrier and collapse of air sacs (increased surface tension)
- “white out” on CXR
43
Q
Treatment of ARDS
A
- address underlying cause
- ventilation with positive end-expiratory pressure (PEEP)
44
Q
Neonatal Respiratory Distress Syndrome
A
- due to inadequate surfactant levels
- surfactant is made by type II pneumocytes
- phosphatidylchoine (lecthin) is the major component
- lack of surfactant leads to collapse of air sacs and formation of hyaline membranes
45
Q
Prematurity and Neonatal Respiratory Distress Syndrome
A
- surfactant production begins at 28 wks; adequate levels are not reached until 34 wks
- amniotic fluid lecithin to sphingomyelin ratio is used to screen for lung maturity
- phosphatidylcholine (lecithin) levels increase as surfactant is produced; sphingomyelin remains constant
- a ratio >2 indicates adequate surfactant production
46
Q
Caesarian Section Delivery and Neonatal Respiratory Distress Syndrome
A
-due to lack of stress-induced steroids; steroids increase synthesis of surfactant
47
Q
Maternal Diabetes and Neonatal Respiratory Distress Syndrome
A
-insulin decreases surfactant production
48
Q
Clinical Features of Neonatal Respiratory Distress Syndrome
A
- increasing respiratory effort after birth, tachypnea with use of accessory muscles, and grunting
- hypoxemia with cyanosis
- diffuse granularity of the lung (“ground-glass” appearance) on CXR
49
Q
Complications of Neonatal Respiratory Distress Syndrome
A
- hypoxemia increases the risk for persistence of patent ductus arteriosus and necrotizing enterocolitis
- supplemental oxygen increases the risk for free radial injury
- retinal injury leads to blindness
- lung damage leads to bronchopulmonary dysplasia
50
Q
Key Risk Factors of Lung Cancer
A
- cigarette smoke, radon, and asbestos
- cigarette smoke contains over 60 carcinogens; 85% of lung cancer occurs in smokers
- polycyclic aromatic hydrocarbons and arsenic are particularly mutagenic
- cancer risk is directly related to the duration and amount of smoking (“pack years”)
- radon is formed by radioactive decay of uranium, which is present in soil
- radon accumulates in closed spaces such as basements
- responsible for most of the public exposure to ionizing radiation; 2nd most frequent cause of lung carcinoma in US
- increased risk of lung cancer is also seen in uranium miners
51
Q
Presenting Symptoms of Lung Cancer
A
- nonspecific
- cough, weight loss, hemoptysis, and postobstructive pneumonia
52
Q
Imaging in Lung Cancer
A
- reveals solitary nodule (“coin-lesion”); biopsy is necessary for a diagnosis of cancer
- benign lesions, which often occur in younger patients, can also produce a “coin-lesion”
- granuloma - often due to TB or fungus (especially Histoplasma in the Midwest)
- bronchial hamartoma - benign tumor composed of lung tissue and cartilage; often calcified on imaging
53
Q
Small Cell Carcinoma
A
- poorly differentiated small cells; arises from neuroendocrine (Kulchitsky) cells
- associated with male smokers
- location is central
- rapid growth and early metastasis; may produce ADH or ACTH or cause Eaton-Lambert syndrome (paraneoplastic syndromes)
54
Q
Squamous Cell Carcinoma
A
- non-small cell carcinoma
- keratin pearls or intercellular bridges
- most common tumor in male smokers
- central in location
- may produce PTHrP
55
Q
Adenocarcinoma
A
- non-small cell carcinoma
- characterized by glands or mucin
- most common tumor in nonsmokers and female smokers
- peripheral in location
56
Q
Large Cell Carcinoma
A
- poorly differentiated large cells (no keratin pearls, intercellular bridges, glands, or mucin)
- associated with smoking
- central or peripheral in location
- poor prognosis
57
Q
Bronchioloalveolar Carcinoma
A
- columnar cells that grow along preexisting bronchioles and alveoli; arises from Clara cells
- not related to smoking
- peripheral in location
- may present with pneumonia-like consolidation on imaging; excellent prognosis
58
Q
Carcinoid Tumor
A
- non-small cell carcinoma
- well differentiated neuroendocrine cells; chromogranin positive
- not related to smoking
- central or peripheral; when central, classically forms a polyp-like mass in the bronchus
- low-grade malignancy; rarely, can cause carcinoid syndrome
59
Q
Metastasis to Lung
A
- most common sources are breast and colon carcinoma
- multiple “cannon-ball” nodules on imaging
- more common than primary tumors
60
Q
TNM Staging (T) - Tumor Size and Local Extension
A
- pleural involvement is classically seen with adenocarcinoma
- obstruction of SVC leads to distended head and neck veins with edema and blue disoloration of arms and face (SVC syndrome)
- involvement of recurrent laryngeal (hoarseness) or phrenic (diaphragmatic paralysis) nerve
- compression of sympathetic chain leads to Horner syndrome and anhidrosis; usually due to an apical (Pancoast) tumor)
61
Q
TNM Staging (N)
A
-spread to regional lymph nodes (hilar and mediastinal)
62
Q
TNM Staging (M)
A
-unique site of distant metastasis is the adrenal gland
63
Q
Pneumothorax
A
-accumulation of air in the pleural space
64
Q
Spontaneous Pneumothorax
A
- due to rupture of an emphysematous bleb; seen in young adults
- results in collapse of a portion of the lung; trachea shifts to the side of collapse
65
Q
Tension Pneumothorax
A
- arises when penetrating chest wall injury
- air enter the pleural space, but cannot exit
- trachea is pushe dopposite to the side of injury
- medical emergency; treated with insertion of a chest tube
66
Q
Mesothelioma
A
- malignant neoplasm of mesothelial cells
- highly associated with occupational exposure to asbestos
- presents with recurrent pleural effusions, dyspnea, and CP
- tumor encases the lung
