CH9 - Respiratory Tract Pathology Flashcards
What is rhinitis?
Inflammation of the nasal mucosa;
What is the most common cause of rhinitis?
adenovirus
What does rhinitis present with?
sneezing, congestion, and runny nose (common cold)
What is allergic rhinitis?
a subtype of rhinitis due to a type I hypersensitivity reaction (e.g. to pollen)
What is allergic rhinitis characterized by?
an inflammatory infiltrate with eosinophils
What is allergic rhinitis characterized by?
associated with asthma and eczema
What is a nasal polyp?
Protrusion of edematous, inflamed nasal mucosa
What is a nasal polyp usually secondary to?
repealed bouts of rhinitis; also occurs in cystic fibrosis and aspirin - intolerant asthma
What is aspirin-intolerant asthma characterized by?
the triad of asthma, aspirin induced bronchospasms, and nasal polyps;
What is the incidence of asprin-intolerant asthma in asthmatic adults?
seen in 10% of asthmatic adults
What is angiofibroma?
Benign tumor of nasal mucosa composed of large blood vessels and fibrous tissue
In whom is angiofibroma classically seen?
in adolescent males
What does angiofibroma present with?
profuse epistaxis
What is nasopharyngeal carcinoma?
Malignant tumor of nasopharyngeal epithelium
What is nasopharyngeal carcinoma associated with?
EBV
Who is nasopharyngeal carcinoma classically seen in?
African children and Chinese adults
What happens in a biopsy of nasopharyngeal carcinoma?
usually reveals pleomorphic keratin-positive epithelial cells (poorly differentiated squamous cell carcinoma) in a background of lymphocytes
How does nasopharyngeal carcinoma often present?
with involvement of cervical lymph nodes
What is acute epiglottitis?
Inflammation of the epiglottis
What is the most common cause of acute epiglottitis?
H. influenzae type b especially in nonimmunized children
What does acute epiglottitis present with?
high fever, sore throat, drooling with dysphagia, muffled voice, and inspiratory stridor; risk of airway obstruction
What is laryngotracheobronchitis?
(croup) Inflammation of the upper airway
What is the most common cause of laryngotracheobronchitis?
parainfluenza virus
What does laryngotracheobronchitis present with?
a hoarse, (barking) cough and inspiratory stridor
What is a vocal cord nodule?
(singer?s nodule) nodule that arises on the true vocal cord
What is a vocal cord nodule due to?
excessive use of vocal cords, usually bilateral
What is a vocal cord nodule composed of?
degenerative (myxoid) connective tissue
How does a vocal cord nodule present?
with hoarseness; resolves with resting of voice
What is laryngeal papilloma?
Benign papillary tumor of the vocal cord
What is laryngeal papilloma due to?
HPV 6 and 11
What is usually the difference between papillomas in adults children?
Papilloma are usually single in adults and multiple in children.
What does laryngeal papilloma present with?
hoarseness
What is laryngeal carcinoma?
squamous cell carcinoma usually arising from the epithelial lining of the vocal cord
What are the risk factors for laryngeal carcinoma?
alcohol and tobacco; can rarely arise from a laryngeal papilloma
What does laryngeal carcinoma present with?
hoarseness; other signs include cough and stridor
What are some pulmonary infections?
Pneumonia, lobar pneumonia, bronchopneumonia, interstitial (atypical pneumonia), aspiration pneumonia, tuberculosis
What is pneumonia?
Infection of the lung parenchyma
When does pneumonia occur?
when normal defenses are impaired (e.g.. impaired cough reflex, damage to mucociliary escalator, or mucus plugging)
What are the clinical features of pneumonia?
include fever and chills, productive cough with yellow-green (pus) or rusty (bloody) sputum, tachypnea with pleuritic chest pain, decreased breath sounds, dullness to percussion, and elevated WBC count
How is the diagnosis for pneumonia made?
by chest x-ray, sputum gram stain and culture, and blood cultures.
What are the three patterns that are classically seen on chest x-ray for pneumonia?
lobar pneumonia, bronchopneumonia, and interstitial pneumonia.
What is lobar pneumonia?
Characterized by consolidation of an entire lobe of the lung
What are the most common causes for lobar pneumonia?
Usually bacterial; most common causes are Streptococcus pneumoniae (95%) and Klebsiella pneumoniae
What are the classic gross phases of lobar pneumonia?
1) Congestion, 2) red hepatization, 3) gray hepatization, 4) resolution
In lobar pneumonia what is the congestion due to?
congested vessels and edema
In lobar pneumonia what is red hepatization due to?
exudate, neutrophils, and hemorrhage tilling the alveolar air spaces, giving the normally spongy lung a solid consistency
In lobar pneumonia what is gray hepatization due to?
degradation of red cells within the exudate
What is bronchopneumonia?
Characterized by scattered patchy consolidation centered around bronchioles; often multifocal and bilateral
What is bronchopneumonia caused by?
a variety of bacterial organisms
What is interstitial (atypical) pneumonia characterized by?
diffuse interstitial infiltrates
How does interstitial (atypical) pneumonia present?
with relatively mild upper respiratory symptoms (minimal sputum and low fever); atypical presentation
What is interstitial (atypical) pneumonia caused by?
bacteria or viruses
What is the most common cause of community-acquired pneumonia?
Streptococcus pneumoniae
What is streptococcus pneumonia usually seen in?
middleaged adults and elderly
Who does Klebsiella pneumoniae affect?
malnourished and debilitated individuals, especially elderly in nursing homes, alcoholics, and diabetics (enteric flora that is aspirated).
What does Klebsiella pneumoniae result in?
Thick mucoid capsule results in gelatinous sputum (currant jelly); often complicated by abscess
What are the causes of bronchopneumonia?
Staphylococcus aureus, haemophilus influenzae, Pseudomonas aeruginosa, Moraxella calarrhalis, Legionella pnemnophila
What is the most common cause of secondary pneumonia?
Staphylococcus aureus
What is secondary pneumonia?
bacterial pneumonia superimposed on a viral upper respiratory tract infection
What is secondary pneumonia caused by staphylococcus aureus often complicated by?
abscess or emphyzema
Haemophilus influenzae is the most common cause of what type of pneumonia?
secondary pneumonia and pneumonia superimposed on COPD
How does haemophilus influenzae affect COPD?
It results in exacerbation of COPD?
What does pseudomonas aeruginosa cause?
Pneumonia in cystic fibrosis patients
What high yield association should be made with moraxella calarrhalis?
Community-acquired pneumonia and pneumonia super imposed on COPD (leads to exacerbation of COPD)
What high yield association should be made with Legionella pnemnophila?
Community-acquired pneumonia, pneumonia superimposed on COPD, or pneumonia in immunocompromised states;
How is Legionella pnemnophila transmitted?
from water source
How is Legionella pnemnophila best visualized?
Its an intracellular organism best visualized by silver stain
What is the most common cause of atypical pneumonia?
Mycoplasma pneumonia
What is the high yield association with mycoplasma pneumoniae?
Most common cause of atypical pneumonia, usually affects young adults (classically, military recruits or college students living in a dormitory).
What are the complications for mycoplasma pneumoniae?
they include autoimmune hemolytic anemia (IgM against I antigen on RBCs causes cold hemolytic anemia) and erythema multiforme. Not visibie on gram stain due to lack of cell wall
What is the second most common cause of atypical pneumonia in young adults?
Chlamydia pneumoniae
What is the most common cause of atypical pneumonia in infants?
Respiratory syncytial virus (RSV)
What causes atypical pneumonia with posttransplant immunosuppressive therapy?
Cytomegalovirus (CMV)
What does influenza virus cause?
atypical pneumonia in the elderly, immunocompromised, and those with preexisting lung disease
What does Influenza virus also increase the risk for?
superimposed S aureus or H influenzae bacterial pneumonia
What does coxiella burnetii cause?
atypical pneumonia with high fever (Q fever);
Who is coxiella burnetii seen in?
farmers and veterinarians
What happens to coxiella spores?
They are deposited on cattle by ticks or are present in cattle placentas
What is coxiella?
it is a rickettsial organism,
How is coxiella distinct from most rickettsiae?
because it (1) causes pneumonia, (2) does not require an arthropod vector for transmission (survives as highly heat-resistant endospores), and (3) does not produce a skin rash.
What is aspiration pneumonia seen in?
patients at risk for aspiration (e.g., alcoholics and comatose patients)
What is aspiration pneumonia most often due to?
anaerobic bacteria in the oropharynx (e.g., Bacteroides, Fusobacterium, and Peptococcus)
What does aspiration pneumonia classically result in?
a right lower lobe abscess
What is the anatomical difference between the right and left main stem bronchus?
branches at a less acute angle than the left.
What is tuberculosis due to?
inhalation of aerosolized mycobacterium tuberculosis
What arises with initial tuberculosis exposure?
Primary TB
What does primary TB result in?
focal, caseating necrosis in the lower lobe of the lung and hilar lymph nodes that undergoes fibrosis and calcification, forming a Ghon complex
What are generally the symptoms for primary TB?
Generally asymptomatic but leads to a positive PPD
What does secondary TB arise with?
reactivation of mycobacterium tuberculosis
What is reactivation of mycobacterium tuberculosis in secondary TB commonly due?
AIDS; may also be seen with aging
Where does secondary TB occur?
at apex of lung (high oxygen tension)
What does secondary TB form?
cavitary foci of caseous necrosis; may also lead to miliary pulmonary TB or tuberculous bronchopneumonia
What are the clinical features of secondary TB?
include fevers and night sweats, cough with hemoptysis, and weight loss.
What does biopsy in secondary TB reveal?
caseating granulomas, AFB stain reveals acid-fast bacilli
How might secondary TB spread?
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).
What is COPD?
Group of diseases characterized by airway obstruction; lung does not empty, and air is trapped.
What happens to the FVC and FEV in COPD?
Volume of air that can be forcefully expired is decreased (FVC), especially during the first second of expiration (FEV) results in decreased FEV:FVC ratio
What happens to total lung capacity in COPD and why?
Total lung capacity (TLC) is usually increased due to air trapping.
What happens in chronic bronchitis?
Chronic productive cough lasting at least 3 months over a minimum of 2 years; highly associated with smoking
What characterizes chronic bronchitis?
hypertrophy of bronchial mucinous glands
What does chronic bronchitis lead to?
increased thickness of mucus glands relative to overall bronchial wall thickness (Reid index increases to > 50%; normal is < 40%).
What are the clinical features for chronic bronchitis?
- Productive cough due to excessive mucus production 2. Cyanosis (blue bloaters) Mucus plugs trap carbon dioxide; increased PaCO2, and decreased PaO2
In chronic bronchitis what is there an increased risk of?
infection and cor pulmonale
What is emphysema?
Destruction of alveolar air sacs
What does emphysema result in?
Loss of elastic recoil and collapse of airways during exhalation results in obstruction and air trapping.
What is emphysema due to?
imbalance of proteases and antiproteases
What does inflammation in the lung normally lead to?
release of proteases by neutrophils and macrophages.
What neutralizes proteases?
A1-antitrypsin (A1AT)
In emphysema what leads to destruction of the alveolar air sac?
Excessive inflammation or lack of A1AT
What is the most common cause of emphysema?
Smoking
How does smoking lead to emphysema ?
- Pollutants in smoke lead to excessive inflammation and protease-mediated damage. 2. Results in centriacinar emphysema that is most severe in the upper lobes
AIAT deficiency relate to emphysema?
It is a rare cause of emphysema.
How does A1AT deficiency lead to emphysema?
- Lack of antiprotease leaves the air sacs vulnerable to protease-mediated damage. 2. Results in panacinar emphysema that is most severe in the lower lobes 3. Liver cirrhosis may also be present.
What is A1AT deficiency due to?
misfolding of the mutated protein
What happens to mutant A1AT?
it accumulates in the endoplasmic reticulum of hepatocytes, resulting in liver damage.
What is a PAS stain?
Periodic acid-Schiff stain
What does biopsy of A1AT reveal?
Pink, PAS-positive globules in hepatocytes
In A1AT deficiency what is disease severity based on?
the degree of A1AT deficiency.
For A1AT deficiency induced emphysema, what is the normal allele?
PiM; two copies are usually expressed (PiMM).
For A1AT deficiency induced emphysema what is the most common clinically relevant mutation and what does it result in?
PiZ which results in significantly low levels of circulating A1AT
What is usually seen in PiMZ heterozygotes?
they are usually asymptomatic with decreased circulating levels of A1AT
In PiMZ what is there significant risk for?
emphysema with smoking exists
What is seen in PiZZ homozygotes?
significant risk for panacinar emphysema and cirrhosis.
What are the clinical features of emphysema?
- Dyspnea and cough with minimal sputum 2. Prolonged expiration with pursed lips (pink-pu lier) 3. Weight loss 4. Increased anterior-posterior diameter of chest (barrel-chest) 5. Hypoxemia and cor pulmonale (late complications)
Why is there hypoxemia in emphysema?
due to destruction of capillaries in the alveolar sac)
What is asthma?
Reversible airway bronchoconstriction
What is asthma most often due to?
allergic stimuli (type I hypersensitivity)
When does asthma present?
in childhood; often associated with allergic rhinitis, eczema, and a family history of atopy
What is atopy?
(atopic allergy), a genetic predisposition toward the development of immediate hypersensitivity reactions against common environmental antigens
For the Pathogenesis of asthma, what do the allegens induce?
- Allergens induce TH2 phenotvpe in CD4+ T cells of genetically susceptible individuals 2. TH2 cells secrete IL-4, IL-5, IL-10
What does IL-4 do?
mediates class switch to IgE
What does IL-5 do?
attracts eosinophils
What does IL-10 do?
stimulates TH2 cells and inhibits THl
For the Pathogenesis of asthma, what does reexposure to allergen lead to?
IgE-mediated activation of mast cells.
What does activation of mast cells lead to?
Release of preformed histamine granules and generation of leukotrienes C4, D4, and E4
For the Pathogenesis of asthma what does release of preformed histamine granules and leukotrine generation lead to?
bronchoconstriction, inflammation, and edema (early phase reaction),
For the pathogenesis of asthma, describe inflammation after reexposure to allergen?
There is inflammation especially major basic protein derived from eosinophils, damages cells and perpetuates bronchoconstriction (late-phase reaction).
What are the clinical features of asthma?
They are episodic and related to allergen exposure. 1. Dyspnea and wheezing 2. Productive cough, classically with spiral-shaped mucus plugs (Curschmann spirals) and eosinophil-derived crystals (Charcot-Leyden crystals) 3. Severe, unrelenting attack can result in status asthmaticus and death.
What are curschmann spirals?
Spiral shaped mucus plugs
What are some nonallergic causes for asthma?
Asthma may also arise from nonallergic causes such as exercise, viral infection, aspirin (e.g., aspirin intolerant asthma), and occupational exposures.
What is bronchiectasis?
Permanent dilatation of bronchioles and bronchi; loss of airway tone results in air trapping.
What is bronchiectasis due to?
necrotizing inflammation with damage to airway walls.
What are the causes for bronchiectasis?
- Cystic fibrosis 2. Kartagener syndrome 3. Tumor or foreign body 4. Necrotizing infection 5. Allergic bronchopulmonary aspergillosis
What is Kartagener syndrome?
inherited defect of the dynein arm, which is necessary for ciliary movement.
What is Kartagener syndrome 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)
What is allergic bronchopulmonary aspergillosis?
Hypersensitivity reaction to aspergillus leads to chronic inflammatory damage;
Allergic bronchopulmonary aspergillosis is usually seen in whom?
individuals with asthma or cystic fibrosis
What are the clinical features for bronchiectasis?
- Cough, dyspnea, and foul-smelling sputum
What are the complications for bronchiectasis?
hypoxemia with cor pulmonale and secondary (AA) amyloidosis.
What are the restrictive diseases?
1) idiopathic pulmonary fibrosis 2) pneumoconioses 3) sarcoidosis 4) hypersensitivity pneumonitis
What characterizes restrictive diseases?
restricted filling of the lung; decreased TLC and decreased FVC; FEV:FVC ratio is increased.
What are restrictive diseases most commonly due to?
interstitial diseases of the lung; may also arise with chest wall abnormalities (e.g., massive obesity)
What is idiopathic pulmonary fibrosis?
Fibrosis of lung interstitium
What is the etiology for idiopathic pulmonary fibrosis?
unknown. Likely related to cyclical lung injury; TGF-beta from injured pneumocytes induces fibrosis. Secondary causes of interstitial fibrosis must be excluded
What are the secondary causes of interstitial fibrosis?
drugs (e.g., bleomycin and amiodarone) and radiation therapy
What are the clinical features for idiopathic pulmonary fibrosis?
- Progressive dyspnea and cough 2. Fibrosis on lung CT; initially seen in subpleural patches, but eventually results in diffuse fibrosis with end-stage honeycomb lung
What is the treatment for idiopathic pulmonary fibrosis?
lung transplantation.
What is pneumoconioses?
Interstitial fibrosis due to occupational exposure;
What does pneumoconioses require in order to develop?
chronic exposure to small particles that are fibrogenic
In pneumoconioses what induces fibrosis?
Alveolar macrophages engulf foreign particles and induce fibrosis.
What is the exposure for Coal Workers Pneumoconiosis?
Carbon dust; seen in coal miners
What are the pathological findings for Coal Workers’ Pneumoconiosis?
Massive exposure leads to diffuse fibrosis (black lung); associated with rheumatoid arthritis (Caplan syndrome)
How is Coal Workers’ Pneumoconiosis related to anthracosis?
Mild exposure to carbon (e.g., pollution) results in anthracosis (collections of carbon-laden macrophages); not clinically significant
In silicosis, what is the exposure?
Silica; seen in sand blasters and silica miners
In silicosis what are the pathologic findings?
Fibrotic nodules in upper lobes of the lung
In silicosis what is there an increased risk for?
TB; silica impairs phagolysosome formation by macrophages.
In Berylliosis, what is the exposure?
Beryllium; seen in beryllium miners and workers in the aerospace industry
In berylliosis what are the pathological findings?
Noncaseating granulomas in the lung, hilar lymph nodes, and systemic organs
In berylliosis what is there an increased risk for?
lung cancer
In asbestosis, what is the exposure?
Asbestos fibers; seen in construction workers, plumbers, and shipyard workers
In asbestosis what are the pathologic findings?
Fibrosis of lung and pleura (plaques) with increased risk for lung carcinoma and mesothelioma;
In asbestosis, which is more common in exposed individuals?
lung carcinoma is more common than mesothelioma
What may the lesions in asbestosis contain?
Lesions may contain long, goldenbrown fibers with associated iron (asbestos bodies), which confirm exposure to asbestos
In asbestosis what are seen in the cells?
Characteristic stellate inclusions (asteroid bodies) are often seen within giant cells of the granulomas
What is sarcoidosis?
Systemic disease characterized by noncaseating granulomas in multiple organs
In whom is sarcoidosis classically seen in?
African American females
What is the etiology for sarcoidosis?
it is unknown; likely due to CD4+ helper T-cell response to an unknown antigen
In sarcoidosis what do granulomas most commonly involve?
the hilar lymph nodes and lung leading to restrictive lung disease.
In sarcoidosis what are 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,
What syndrome does sarcoidosis mimic?
Sjogren syndrome
What are the clinical features for sarcoidosis?
- Dyspnea or cough (most common presenting symptom) 2. Elevated serum ACE 3. Hypercalcemia
In sarcoidosis, why is there hypercalcemia?
1-alpha hydroxylase activity of epithelioid histiocytes converts vitamin D to its active form
In sarcoidosis what is the most common presenting symptom?
Dyspnea or cough
What is the treatment for sarcoidosis?
steroids; often resolves spontaneously without treatment.
What is hypersensitivity pneumonitis?
Granulomatous reaction to inhaled organic antigens (e.g., pigeon breeder’s lung)
How does hypersensitivity pneumonitis present?
with fever, cough, and dyspnea hours after exposure; resolves with removal of the exposure
In hypersensitivity pneumonitis what does chronic exposure lead to?
interstitial fibrosis.
What is seen in pulmonary hypertension?
high pressure in the pulmonary circuit (mean arterial pressure > 25 mm Hg; normal is 10 mm Hg)
What is pulmonary hypertension characterized by?
atherosclerosis of the pulmonary trunk, smooth muscle hypertrophy of pulmonary arteries, and intimal fibrosis;
With pulmonary hypertension what are seen with severe, long-standing disease?
plexiform lesions
What does pulmonary hypertension lead to?
right ventricular hypertrophy with eventual cor pulmonale
What does pulmonary hypertension present with?
exertional dyspnea or right-sided heart failure
What is pulmonary hypertension subclassified as?
primary or secondary based on etiology
What is primary pulmonary hypertension classically seen in?
young adult females
What is the etiology for primary pulmonary hypertension?
unknown; some familial forms are related to inactivating mutations of BA1PR2, leading to proliferation of vascular smooth muscle.
What is secondary pulmonary hypertension 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
What are the respiratory distress syndromes?
1) acute respiratory distress syndrome 2) neonatal respiratory distress syndrome
What is acute respiratory distress syndrome?
Diffuse damage to the alveolar-capillary interface (diffuse alveolar damage)
What happens in acute respiratory distress syndrome?
Leakage of protein-rich fluid leads to edema and formation of hyaline membranes in alveoli
What are the clinical features for acute distress syndrome?
- Hypoxemia and cyanosis with respiratory distress due to thickened diffusion barrier and collapse of air sacs (increased surface tension) 2. White-out on chest x-ray
Acute respiratory distress syndrome is secondary to what disease processes?
sepsis, infection, shock, trauma, aspiration, pancreatitis, DIG, hypersensitivity reactions, and drugs.
Why is acute respiratory distress syndrome secondary to so many diseases?
Activation of neutrophils induces protease-mediated and free radical damage of type 1 and II pneumocytes.
What is the treatment for acute respiratory distress syndrome?
- Address underlying cause 2. Ventilation with positive end-expiratory pressure (PEEP)
For acute respiratory distress syndrome what might complicate recovery?
interstitial fibrosis; damage and loss of type II pneumocytes leads to scarring and fibrosis.
What is neonatal respiratory distress syndrome?
Respiratory distress due to inadequate surfactant levels
Surfactant is made by what?
type II pneumocytes;
What is the major component in surfactant?
phosphatidylcholine (lecithin)
What does surfactant do?
decreases surface tension in the lung, preventing collapse of alveolar air sacs after expiration.
What does lack of surfactant lead to?
collapse of air sacs and formation of hyaline membranes.
What is neonatal respiratory distress syndrome associated with?
1) Prematurity 2) Cesarian section delivery 3) Maternal diabetes
When does surfactant production begin?
28 weeks
When are adequate levels of surfactant reached?
34 weeks
What is used to screen for lung maturity?
Amniotic fluid lecithin to sphingomyelin ratio
What is the relationship between phosphatidylcholine (lecithin) levels and surfactant?
phosphatidylcholine (lecithin) levels increase as surfactant is produced
What is the relationship between sphingomyelin levels and surfactant?
sphingomyelin remains constant as surfactant is produced
What does an amniotic fluid lecithin to sphingomyelin ratio >2 indicate?
adequate surfactant production
Why is neonatal respiratory distress syndrome associated with caesarian section delivery?
due to lack of stress-induced steroids; steroids increase synthesis of surfactant,
Why is neonatal respiratory distress syndrome associated with maternal diabetes?
Insulin decreases surfactant production
What are the clinical features for neonatal respiratory distress syndrome?
- Increasing respiratory effort after birth, tachypnea with use of accessory muscles, and grunting 2. Hypoxemia with cyanosis 3. Diffuse granularity of the lung (ground-glass appearance) on x-ray
What are the complications for neonatal respiratory distress syndrome?
- Hypoxemia increases the risk for persistence of patent ductus arteriosus and necrotizing enterocolitis. 2. Supplemental oxygen increases the risk for free radical injury. Retinal injury leads to blindness; lung damage leads to bronchopulmonary dysplasia,
What is the most common cause of cancer mortality in the US?
Lung cancer; average age at presentation is 60 years.
What are the key risk factors for lung cancer?
cigarette smoke, radon, and asbestos.
What percentage of lung cancer occurs in smokers?
85% Cigarette smoke contains over 60 carcinogens
For lung cancer what are are particularly mutagenic?
Polycyclic aromatic hydrocarbons and arsenic
How does cancer risk and smoking relate?
Cancer risk is directly related to the duration and amount of smoking (packyears).
What is radon formed by?
radioactive decay of uranium, which is present in soil
Where does radon accumulate?
in closed spaces such as basements
What is responsible for most of the public exposure to ionizing radiation?
radon
What is the 2nd most frequent cause of lung carcinoma in US?
Radon
In addition to smokers and radon increased risk of lung cancer is also seen in what population?
uranium miners.
What are the presenting symptoms for lung cancer?
they are nonspecific (cough, weight loss, hemoptysis, and postobstructive pneumonia)
In lung cancer, what does imaging often reveal?
a 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
What are some examples of benign lesions that appear as coin lesions on imaging?
Granuloma and bronchial hamartoma
What is the benign lesion seen in a granuloma often due to?
TB or fungus (especially Hittoplasma in the Midwest)
What is the benign lesion seen in bronchial hamartoma due to?
benign tumor composed of lung tissue and cartilage; often calcified on imaging
Lung carcinoma is classically divided into what 2 categories?
1) small cell carcinoma 2) non-small cell carcinoma
What usually happens in small cell carcinoma?
(15% of cases) usually not amenable to surgical resection (treated with chemotherapy)
What usually happens in non-small cell carcinoma?
(85% of cases) treated upfront with surgical resection (does not respond well to chemotherapy)
What are the subtypes of non-small cell carcinoma?
adenocarcinoma (40%), squamous cell carcinoma (30%), large cell carcinoma (10%), and carcinoid tumor (5%).
What is TNM staging?
- T?Tumor size and local extension 2. N?spread to regional lymph nodes (hilar and mediastinal) 3. M?unique site of distant metastasis is the adrenal gland.
Involvement of what is classically seen with adenocarcinoma?
pleura
What is superior vena cava syndrome?
Obstruction of SVC leads to distended head and neck veins with edema and blue discoloration of arms and face
In regard to TNM, what would hoarseness and diaphragmatic paralysis indicate?
Involvement of recurrent laryngeal (hoarseness) or phrenic (diaphragmatic paralysis) nerve
How is Horner syndrome related to TNM staging?
Compression of sympathetic chain leads to Horner syndrome
How is Horner syndrome characterized?
by ptosis (drooping eyelid), miosis (pinpoint pupil), and anhidrosis (no sweating);
What is Horner syndrome usually due to?
an apical (Pancoast) tumor
What does the N in TNM staging stand for?
spread to regional lymph nodes (hilar and mediastinal)
What does the M in TNM stand for?
unique site of distant metastasis is the adrenal gland.
What is the 5 year survival rate for lung cancer? Explain.
Overall, 15% 5-year survival; often presents late due to the absence of an effective screening method
What is the characteristic histology for small cell carcinoma?
Poorly differentiated small cells; arises from neuroendocrine (Kulchitsky) cells
Who is small cell carcinoma associated with?
Male smokers
What is the location for small cell carcinoma?
Central
What are some characteristics of small cell carcinoma?
Rapid growth and early metastasis; may produce ADH or ACTH or cause Eaton-Lambert syndrome (paraneoplastic syndromes)
What is the characteristic histology for squamous cell carcinoma?
Keratin pearls or intracellular bridges
What is the most common tumor in male smokers?
squamous cell carcinoma
What is the location for squamous cell carcinoma?
Central
What might squamous cell carcinoma produce?
PTHrP (parathyroid hormone ? related protein)
What is the characteristic histology for adenocarcinoma?
Glands or mucin
In whom does adenocarcinoma most commonly affect?
Most common tumor in nonsmokers and female smokers
What is the location for adenocarcinoma?
Peripheral
What is the characteristic histology for large cell carcinoma?
poorly differentiated large cells (no keratin pearls, intercellular bridges, glands, or mucin)
What is large cell carcinoma associated with?
Smoking
What is the location for large cell carcinoma?
Central or peripheral
What is the prognosis for large cell carcinoma?
poor
What is the characteristic for bronchioloalveolar carcinoma?
Columnar cells that grow along preexisting bronchioles and alveoli; arises from Clara cells
From what does bronchioloalveolar carcinoma arise?
From Clara cells
How is bronchioloalveolar carcinoma related to smoking?
Its not
What is the location for bronchioloalveolar carcinoma?
Peripheral
How might bronchioloalveolar carcinoma present?
May present with pneumonia-like consolidation on imaging;
What is the prognosis for bronchioloalveolar carcinoma?
excellent prognosis
What is the characteristic histology for Carcinoid tumor?
Well differentiated neuroendocrine cells; chromogranins positive
How is carcinoid tumor related to smoking?
Its not
What is the location for carcinoid tumor?
Central or peripheral
What does a carcinoid tumor classically form?
A polyp-like mass in the bronchus
Describe the malignancy of a carcinoid tumor?
Low-grade malignancy; rarely, can cause carcinoid syndrome
What is the characteristic histology for metastasis to lung?
Most common sources are breast and colon carcinoma.
What is the location for metastasis to lungs?
Multiple cannonball nodules on imaging
Metastasis to lungs is more common than what type of tumor?
primary tumors
What is a pneumothorax?
An accumulation of air in the pleural space
What is a spontaneous pneumothorax due to?
rupture of an emphysematous bleb
In whom do you see spontaneous pneumothorax?
seen in young adults
What does spontaneous pneumothorax result in?
collapse of a portion of the lung;
In a spontaneous pneumothorax, how can you tell which side collapsed?
trachea shifts to the side of collapse
Tension pneumothorax arises with what?
penetrating chest wall injury
What happens in a tension pneumothorax?
1) Air enters the pleural space, but cannot exit; trachea is pushed opposite to the side of injury. 2) Medical emergency; treated with insertion of a chest tube
Regarding pneumothorax, what does a tracheal shift tell you?
Tension pneumothorax = opposite side of injury, spontaneous pneumothorax = shifts to the side of the collapse
What is mesothelioma?
Malignant neoplasm of mesothelial cells
Mesothelioma is highly associated with what?
Occupational exposure to asbestos
What does mesothelioma present with?
recurrent pleural effusions, dyspnea, and chest pain; tumor encases the lung
