Respiratory Flashcards
What disorder should you think about in a child with nasal polyps?
Cystic Fibrosis
Why should you avoid aspirin in patients with nasal polyps?
Adults with nasal polyps and asthma are at a high likelihood of aspirin allergy (aspirin intolerant asthma).
What subgroup is angiofibroma of the nasal mucosa most commonly seen in?
Adolescent males (almost exclusively)
What virus can cause nasopharyngeal CA?
EBV
What two demographics are at high risk for nasopharyngeal cancer from EBV?
African children, Chinese adults
Describe the histology of nasopharyngeal carcinoma.
Pleomorphic keratin-positive epithelial cells in a background of lymphocytes
What is the #1 cause of acute epiglottitis?
H. influenza b
What viruses cause laryngeal papillomas?
HPV 6 and 11
How many papillomas are seen in adults with laryngeal papillomas?
One
How many papillomas are seen in children with laryngeal papillomas?
Multiple
What are the two most common causes of lobar pneumonia?
S. pneumo and K. pneumoniae
What are the 4 phases of lobar pneumonia?
Congestion, red hepatization (lots of RBCs), grey hepatization (RBCs broken down), resolution
Which cells are stem cells of lungs that help regenerate the alveolar air sacs after lung damage?
Type II pneumocytes
Grossly, how does bronchopneumonia appear?
Patchy (“shotgun”) appearance
What is the #1 cause of bacterial pneumonia following a viral infection of the lung (influenza)?
S. aureus
What are two major complications of staph aureus pneumonia?
Abscess, empyema
What two bacteria are most commonly seen in patients with COPD?
H. influenzae, M. catarrhalis
What stain is best to identify Legionella Pneumophila?
Silver stain
What is the #1 cause of atypical pneumonia in infants?
RSV
What is the classic location of aspiration pneumonia?
Right lower lobe
Meningitis caused by TB classically presents in what location?
The base of the brain
What happens to the FEV1/FVC ratio in COPD?
Decreases (Both FVC and FEV1 decrease, but FEV1 decreases more)
What is the symptomatic time period necessary for a diagnosis of chronic bronchitis?
Productive cough lasting at least 3 months over a minimum of 2 years.
What is the Reid index and what is its normal value?
Reid index- thickness of mucus glands in bronchi relative to the thickness of the entire wall. Normally <40%.
What is the Reid index in chronic bronchitis?
> 50% (increased thickness of mucinous glands relative to the entire thickness of the bronchial wall).
A “blue bloater” has what disease?
Chronic bronchitis
What causes centriacinar emphysema?
Smoking (usually in upper lobes)
What causes panacinar emphysema?
Alpha 1 antitrypsin deficiency (destroy the entire acinus)
In which lobes is centriacinar emphysema usually found?
Upper (smoke travels up in the lungs)
In which lobes is panacinar emphysema usually found?
Lower lobes
Pink PAS positive globules on liver biopsy is indicative of…
Alpha 1 antitrypsin deficiency
What is the most common mutation seen in A1AT deficiency?
PiZ allele
Where does alpha-1 antitrypsin accumulate in individuals with A1ATD?
Endoplasmic reticulum
Explain the mechanism of wall collapse in emphysema.
Normally, recoil of alveoli serves to hold lower airways open during expiration. When their septa are destroyed in emphysema, they lose this ability, and the airways collapse.
Why do patients with emphysema breathe with pursed lips?
It creates back pressure to keep the small airways open (they would otherwise collapse in emphysema because of loss of recoil from alveoli to keep them open)
What disease does a “pink puffer” have?
Emphysema
What 3 cytokines do TH2 cells secrete?
IL-4, IL-5, IL-10
What does IL-4 do?
Promotes class switching to IgE/IgG
What cytokine is a key eosinophil activator?
IL-5
What are the two mechanisms that cause early inflammation in asthma?
Mast cell destabilization and release of preformed histamine. Production of LTC4, LTD4, LTE4
What are Curschmann spirals?
Twisted mucous plugs admixed with sloughed epithelium in asthma
What are Charcot-Leyden crystals?
Crystals in sputum formed from breakdown of eosinophils in sputum
What is bronchiectasis?
Permanent dilation of bronchioles and bronchi (large airways)
What are some causes of bronchiectasis?
Bronchial obstruction, Kartagener’s syndrome (dysfunction of dynein arms of cilia), CF, allergic bronchopulmonary aspergillosis.
What is paraseptal (distal acinar) emphysema?
Emphysema of distal airway structures - associated with apical bullae that can rupture in tall, thin, male patients, creating a spontaneous pneumothorax.
What happens to the FEV1/FVC in restrictive diseases?
The ratio increases (Both FEV1 and FVC decrease, but FVC decreases more)
What induces fibrosis in idiopathic pulmonary fibrosis?
TGF-beta released from injured pneumocytes
What causes fibrosis in pneumoconiosis?
Alveolar macrophages responding to small particles
What is Caplan syndrome?
Black lung (coal worker pneumoconiosis) + rheumatoid arthritis
What is anthracosis?
A clinically insignificant anthracosis of the lung caused by mild exposure to carbon in pollutants.
What does silica do to alveolar macrophages?
Impairs phagolysosome formation, thus increasing risk for TB (only pneumoconiosis that increases TB risk)
In what lobe of the lung does silicosis typically occur?
Upper lobe (also increases the risk for TB, which preferentially infects upper lobe)
What category of patients are at risk for exposure to beryllium, and what does it cause?
Workers in the aerospace industry. Beryllium exposure causes noncaseating granulomas in the lung (similar to sarcoidosis) and increases risk of lung cancer.
What four general things can be caused by asbestos?
Fibrosis of the lung, fibrosis of the pleura, cancer of the lung, cancer of the pleura (mesothelioma).
What is the most common cancer that individuals exposed to asbestos get?
Lung cancer (bronchogenic) NOT mesothelioma!.
Patients in what occupation are at high risk for exposure to silica?
Sandblasters, miners.
What can cause “eggshell” calcifications of hilar lymph nodes?
Silicosis
What is the pathophysiology of idiopathic pulmonary fibrosis?
Repeated cycles of lung injury and healing with increased collagen deposition.
Where are non-caseating granulomas commonly seen in sarcoidosis?
Lung and hilar lymph nodes
What enzyme is commonly elevated in the blood of patients with sarcoidosis?
ACE
Why do patients with sarcoidosis have hypercalcemia?
Macrophages in non-caseating granulomas have 1-alpha hydroxylase activity and can activate vitamin D.
Explain the signs and symptoms of hypersensitivity pneumonitis.
Granulomatous reaction to inhaled organic antigens (pigeon feces, hay, etc.) with dyspnea, cough, chest tightness, etc. that GOES AWAY with removal of the stimulus. Can lead to interstitial fibrosis. Will see eosinophils in the tissue.
What is a plexiform lesion?
A tuft of capillaries resembling a primitive glomerulus seen in irreversible pulmonary hypertension.
What is normal pulmonary artery pressure?
10-14 mm Hg
What are some signs and symptoms of pulmonary hypertension?
Exertional dyspnea, right sided heart failure, RVH
What gene is inactivated in familial forms of primary pulmonary hypertension?
BMPR2
BMPR2 inactivation leads to…
Proliferation of vascular smooth muscle and pulmonary hypertension
What are some causes of secondary pulmonary hypertension?
Hypoxemia (COPD), increased volume in pulmonary circuit (left heart failure, mitral stenosis), recurrent pulmonary embolism.
What is a sequelae of recurrent pulmonary embolism?
Pulmonary hypertension secondary to thickening of the vascular wall due to repeated embolus deposition.
What is the microscopic hallmark of ARDS?
Formation of thickened hyaline membranes in alveoli.
What causes a diffuse “white out” of the lung on CXR?
ARDS
What cells are damaged in ARDS?
Type I and type II pneumocytes (injury to type II pneumocytes causes fibrosis upon recovery)
What is seen on CXR in newborns with neonatal ARDS?
Diffuse granularity
What test is used to screen for neonatal ARDS?
Lecithin:sphingomyelin ratio (lecithin increases as lungs mature). Ratio >2 = good.
What is the main component of surfactant?
Phosphatidylcholine (lecithin)
What are polycyclic aromatic hydrocarbons?
Extremely carcinogenic compounds found in cigarette smoke.
What two benign lesions can present as “coin lesions” on CXR or CT?
Granuloma and Bronchial hamartoma (Lung tissue and cartilage)
What types of tissue does a bronchial hamartoma contain?
Lung tissue and cartilage
Which type of lung cancer is not amenable to resection?
Small cell
What are some of the paraneoplastic syndromes that can be seen with small cell lung cancer?
Lambert-Eaton syndrome (antibodies against presynaptic calcium channels), ADH-producing tumor, ACTH-producing tumor
What are Kulchitsky cells?
Neuroendocrine cells (small, dark, blue cells) seen in small cell lung cancer.
What is the most common lung tumor in male smokers?
Squamous cell carcinoma
What are two major histologic characteristics of squamous cell carcinoma?
Intercellular bridging or keratin pearls
What is a common paraneoplastic syndrome seen with squamous cell carcinoma?
Hypercalcemia (tumor produces parathyroid-related peptide)
What lung tumor is cavitating?
Squamous cell carcinoma
What protein is released by squamous cell carcinoma to cause hypercalcemia?
Parathyroid hormone-related protein
What is the most common lung tumor in nonsmokers?
Adenocarcinoma
What is the most common lung tumor in female smokers?
Adenocarcinoma
What is the histologic characteristic of adenocarcinoma of the lung?
Glandular appearance with mucin production
Where (anatomically) is adenocarcinoma of the lung typically located?
In the periphery of the lung
Biopsy of a lung mass shows no evidence of intercellular bridging, keratin pearls, gland formation, or mucin. What is it?
Large cell carcinoma.
Bronchioloalveolar carcinoma is a cancer of which cells?
Clara cells
What is the hisologic appearance of bronchioloalveolar carcinoma?
Walls of alveolar air sacs replaced by columnar cells - apparent “thickening” of alveolar walls
What is the classic presentation of bronchioalveolar carcinoma on CXR?
Hazy infiltrates, similar to pneumonia
What is the prognosis of bronchioloalveolar carcinoma?
Excellent
Lung carcinoid tumor can be stained with..
Chromogranin
How can lung carcinoid tumor be differentiated from small cell carcinoma?
Both are neuroendocrine tumors. Small cell carcinoma is poorly differentiated, carcinoid tumor is well differentiated.
What lung tumor presents as a polyp-like mass in the bronchus?
Carcinoid tumor
What is the classic appearance of metastasis to the lungs?
Cannonball appearance - multiple nodules
What is a unique place that lung cancer likes to metastasize?
Adrenal gland
Which primary lung tumor will most commonly affect the pleura?
Adenocarcinoma (grows on the periphery of the lung and can cause pleural puckering)
What are the signs and symptoms of SVC syndrome?
Distended head and neck veins with edema and blue discoloration of the arms and face.
What thoracic tumor shows psammoma bodies on histology?
Mesothelioma
What lung cancer results from a k-ras mutation?
Adenocarcinoma
What is lepidic spread?
Cancer spreading along alveolar septa like a picket fence. Seen in bronchioloalveolar carcinoma.
What lung tumor will have nodular growth with central necrosis and cavitations?
Squamous cell
Biopsy of a lung tumor shows cells with salt and pepper chromatin with nuclear molding. Dx?
Small cell carcinoma
What lung tumor is associated with peripheral leukocytosis/eosinophilis?
Large cell
What lung tumor is associated with amplification of myc oncogenes?
Small cell carcinoma
To what side does the trachea shift in a spontaneous pneumothorax?
The side of the collapsed lung
What is the most common cause of spontaneous pneumothorax?
Rupture of apical blebs (seen in tall, thin males)
To what side does the trachea shift in a tension pneumothorax?
Away from the lesion
What are the three types of atelectasis?
Resorption (obstructive), compression, contraction
What causes resorption atelectasis?
Complete obstruction of airway (asthma, chronic bronchitis, bronchiectasis, foreign bodies)
To which side does the mediastinum shift with resorption atelectasis?
Toward the atelectatic lung
Explain the pathophysiology of resorption atelectasis.
Complete obstruction of the airway causes diminished lung volume. As a result, the mediastinum shifts TOWARDS the atelectatic lung.
How do you treat resorption atelectasis?
Remove the obstruction (it is also known as obstructive atelectasis)
To what side does the mediastinum shift in a compression atelectasis?
AWAY from the atelectatic lung (an example is a tension pneumothorax)
Explain the pathophysiology of compression atelectasis.
Something in the pleural cavity (air, fluid, tumor, etc.) causes compression of the lung, pushing the mediastinum AWAY from the atelectatic lung.
Which form of atelectasis is irreversible?
Contraction
What causes contraction atelectasis?
Fibrotic changes of the lung and/or pleura, preventing full expansion.
What are the 3 most common causes of otitis media?
Strep pneumo, H. influenza, Moraxella catarrhalis (gram - diplococci)
What serotypes of C. trachomatis cause neonatal conjunctivits?
D-K (from mom having an STD)
What are the two causes of neonatal conjunctivitis?
C. trachomatis (D-K), N. gonorrheae
What causes trachoma?
C. trachomatis A-C subtypes
What are the 3 F’s of trachoma?
Fomites, flies, fingers (all 3 spread the disease)
How does trachoma cause blindness?
Repeated infection with C. trachomatis types A-C results in scarring and inversion of the eyelid. The eyelashes abrade the cornea, causing blindness. The disease is spread by the 3 F’s: fingers, flies, fomites.
What is the most common cause of otitis externa?
Pseudomonas
What is the most common cause of viral conjunctivits?
Adenovirus (non-enveloped DNA virus) - swimming pool conjunctivitis.
What is the #1 cause of retinitis in AIDS patients?
CMV (herpesvirus - enveloped DS DNA)
What agar grows Fusarium?
Sabourad dextrose
What is Fusarium, what does it cause, and how do you get it?
Fusarium is a fungus (grows on sabourad dextrose) acquired through homemade contact lens solutions or trauma. It can cause keratitis of the eye and blindness.
What is Acanthamoeba, what does it do to your eyes, and how do you get it?
Acanthamoeba is a parasite acquired from deep water in lakes (association with contact lenses and swimming) that causes keratitis and blindness.
Explain the correlation between toxoplasmosis and blindness.
Mother is exposed (changing cat litter or eating contaminated food) during pregnancy, toxo crosses the placenta, and causes irreversible blindness to the child in the child’s teens or 20s.
What receptor does rhinovirus use to enter cells?
ICAM-1 (zinc blocks ICAM-1, hence ZICAM)
What are some signs and symptoms of epiglottitis and in what patient population are you concerned about it?
Fever, sore throat, drooling, “catchers-stance”, hoarsness, dysphagia. Concerned in unvaccinated individuals because it is caused by Hib.
What causes the green color of sputum?
Myeloperoxidase
After a lung transplant, what is most commonly attacked in a chronic rejection?
Small airways (bronchioles - bronchiolitis obliterans)
What is asbestosis?
Formation of fibrocalcific plaques on the parietal pleura with subsequent thickening and fibrosis of the lower lung.
What are ferruginous bodies?
Asbestos covered with a protein-iron matrix.
Which parts of the respiratory tree are within the conducting zone?
Large airways: nose, pharynx, trachea and bronchi
small airways: bronchioles and terminal bronchioles
Where in the respiratory tree does cartilage and goblet cells extend to?
The end of bronchi
What is the purpose of the anatomic dead space of the respiratory tree?
The conducting zone warms, humidifies and filters the air
What is the epithelial lining to the end of the terminal bronchioles before you get into the respiratory zone?
pseudostratified ciliated columnar cells to beat mucus up and out of the lungs