Respiratory pathology Flashcards
What causes congenital pulmonary cysts?
Caused by premature separation of the embryonic foregut
Bronchiogenic cyst is …….
congenital pulmonary cyst, centrally located and may be connected to the bronchi/bronchioles. It is lined by ciliated bronchial epithelium. Single or multiple
* Rupture may cause hemoptysis or pneumothorax
Hypoplasia or missing of bronchial cartilage will cause ……
over inflation of the lung due to bronchial obstruction
Bacterial pneumonia occurs when …..
pulmonary defense mechanisms are compromised (decreased cough, macrophage phagocytic defect, pulmonary edema, bronchial injury etc…)
* Immunocompromised patients are at risk also
Define bronchopneumonia
- It is caused by ???
- Clinical features?
- Complications??
Patchy consolidations of one or more lobes, usually in the bases (due to gravity)
- Caused by H. influenzae, staph aureus, Strep. pneumoniae, Pseudomonas or even fungi.
- Features: productive cough, fever, rales, chest pain. X-ray shows focal opacities
- Abscess, empyema, pericarditis, respiratory failure, bacteremia with metastasis of infection
What is the microscopic finding of bronchopneumonia?
purulent exudate dominated by neutrophils
Define lobar pneumonia
- Clinical features??
* Complications??
Infection by streptococcus pneumoniae which spreads throughout the lobe “With consolidation”
- Acute onset of fever, chills, watery sputum followed by rusty colored sputum (later), orthopnea, dyspnea, cyanosis
- Abscess, exudate, empyema, bacteremia, metastasis to liver, spleen, heart, joints, kideny and pericardium
Pneumoniae in alcoholics and diabetics are usually caused by …….
Klebsiella
* The sputum resembles currant jelly
Red hepatization is ……
congestion of the lung with RBC, neutrophil and fibrin. Characteristic of lobar pneumonia
* It is followed by gray hepatization, when the RBC breakdown begin and and exudate accumulates
Why viral and mycoplasmal pneumonia are called “Atypical” pneumonia??
because they lack “Exudate” and the inflammation is found in the lung interstitium and alveolar septae (interstitial pneumonia)
* Viral pneumonia is more common in 2-3 years age
What are the causative agents for atypical pneumonia?
Influenza A & B virus, mycoplasma pneumoniae (common in crowded conditions), rhinovirus, and respiratory syncytial virus (RSV)
What is the most important clinical feature for atypical pneumonia?
* What is the gross pathology of the lesion?
Dry cough
* Uni or bilateral involvement in one or more lobes. Red blue and congested interstitium, but without consolidation (no exudate/pus), no pleural involvement
Pneumocystic carinii pneumonia is ……
* What are the symptoms
a fungal infection of the lungs. Common in immunocompromised patients, undernourished children, and oncology patients
* There is bilateral interstitial infiltrate on Xray. Also, fever, dyspnea, hypoxia
Define pulmonary abscess
- What are the clinical features?
* It is caused by ……
an area of inflammation with a central region of liquefactive necrosis
- There is fever, paroxysmal cough with foul smelling purulent or sanguineous sputum. Air fluid level is seen on Xray, dyspnea, chest pain
- Caused by aerobic and mouth anaerobes (like bacteroids, Fusobacterium, Peptostreptococcus)
What are the possible routes of infection for pneumonia?
- Aspiration of gastric content & mouth flora
- Inhalation of bacteria
- Emboli
- Trauma
- Neoplasia with post obstructive pneumonia
- What causes TB?
2. Where does reactivation of TB infection mostly occur??
- Strict aerobic acid fast Mycobacterium tuberculosis
2. In the apex of the lung and renal cortex
Define Ghon complex
The presence of a calcified lesion in the lung and an associated lymph node shown on Xray in TB patients
Primary TB usually affects ……
the lower part of the upper lobe or the upper part of the lower lobe (subjacent to the pleura)
* There is caseous lesions with an ipsilateral caseous lymphnode which drains the affected parenchyma
What are the clinical features for patients with TB??
Mostly asymptomatic. Microphage phagocytosis of tubercle bacilli, then fusion to form epitheliod giant cells, ends with granuloma formation with central caseous necrosis. However, the bacteria survive in the granuloma for years to remit later
Define secondary TB
It is the reactivation of (not reinfection) of old TB. Usually in the areas of high O2 tension (lung apices)
* Only 10% of patients develop secondary infection
Define Miliary TB
spread of TB infection via blood or lymph.
* Systemic spread is possible after erosion of the pulmonary vein
Define COPD and what are its types
Increased resistance to airflow during inspiration and expiration due to obstruction
- Emphysema
- Asthma
- Bronchiectasis
- Chronic bronchitis
What could be the cause of emphysema?
destruction of the alveolar septae distal to the terminal bronchiole secondary to ischemia. There is ↑ in total lung capacity, ↑ residual volume, no fibrosis
* Associated with smoking and pollution
What are the two types of emphysema?
- Centrilobular: affecting the central and proximal part of the lobule and sparing the peripheral alveoli. The lungs are not enlarged nor pale unless disease is advanced. Usually in the upper lobes
- Panlobular: hyperinflation & pale lungs due to vessels destruction. There is high crepitance, and little inflammation, ↓ alpha-1 antitrypsin
What are the clinical features and complications of emphysema?
Dyspnea, cough, barrel chest, prolonged expiratory time, cor pulmonale (right heart failure), pink puffers (over ventilation), flattened diaphragm
- Complications include polycythemia, cor pulmonale, pneumothorax
- Due to pink puffers hyperventilation, there is less hypoxemia than blue bloaters (chronic bronchitis)
Chronic bronchitis means ……
persistent cough for at least 3 months for 2 consecutive years
- Cough can be productive or not, the sputum uninfected or purulent
- The lungs are hyperinflated with copious mucus plugging
What could be the causes for chronic bronchitis?
- Chronic irritation: NO2 or SO2
- Recurrent infections (don’t cause it, but perpetuate it)
* The result is mucus plugging due to recurrent infections & irritations, which lead to blocking, inflammation, edema and fibrosis with smooth muscle atrophy. Also, metaplasia or dysplasia of the mucosa is common
What are the clinical features and complications for chronic bronchitis?
dyspnea, persistent productive cough, barrel chest, cyanosis.
- Cor pulmonale may occur due to hypoxia. Dysplasia of the epithelium may cause cancer
- Patients are called blue bloaters due to cyanosis. There is a severe ventilation:perfusion mismatch compared to emphysema
Define Extrinsic asthma (allergic, immune, atopic)
triggered by environmental factors. Spasm mediated by Type I (IgE) hypersensitivity.
- Histamine, leukotrienes, prostoglandin D2 and platelet activation all lead to airway constriction and increase vascular permeability.
- Serum IgE is elevated
- Can be confirmed by a positive skin test to the offending antigen
- Usually, there is a family history
Define intrinsic asthma (non immune)
Follows viral infection (which causes lowering of the vagal threshold to irritants), stress, smoke, cold air, exercise
* There is no family history, IgE levels are normal and skin tests are negative
Define the Aspirin induced asthma
There is a classic triad of asthma, nasal polyps, rhinitis
* It is caused by arachidonic acid
In asthma, the lungs are …….
hyperinflated, with areas of atelectasis, and bronchi/bronchioles occluded by thick mucus, edema, and bronchial wall muscles hypertrophy
* Symptoms include wheezing, cough, dyspnea
Define:
- Curschmann spirals
2. Charcot-Leyeden crystals
- coiled mucinous fibrils sometimes found in the sputum in bronchial asthma
- Eosinophilic crystals found in the sputum of asthmatic patients, and indicate inflammation
Define bronchiectasis
permanent dilatation of airways due to chronic necrotizing infection
* One of the causes is immotile cilia which hinders the ability to remove inhaled bacteria
What is the pathogenesis for bronchiectasis?
- Bronchial obstruction (COPD, foreign body, tumor) leads to atelectasis and air way smooth muscle relaxation
- Infection due to impaired defense against pathogens and injury to ciliary apparatus, with impaired phagocytosis
* Usually the lower lobes are affected, the lumen is filled with purulent exudate
What are the clinical features and complications for bronchiectasis?
Productive cough with foul smelling purulent sputum
* complications include empyema, septic emboli, lung abscess, pneumonia
In restrictive lung disease, decrease compliance leads to …….
small lung volume with high airflow rate
Define the adult respiratory distress syndrome
The final pathway of acute diffuse alveolar damage, which is caused by variety of insults (spesis, trauma, infections etc..)
- Characterized by rapid onset of severe respiratory insufficiency (impaired ventilation)
- Treatment is by mechanical ventilation in ICU
Pneumoconiosis leads to ……
progressive massive fibrosis with diffuse scarring (restrictive lung disease)
In coal workers pneumoconiosis, the clinical features are …..
blackened sputum, massive fibrosis of the lung with possible cor pulmonale
* There is high aggregation of macrophages
Define anthracosis
deposition of carbon in the lungs due to inevitable inhalation
* Not associated with symptomatic disease
Define silicosis
occurs from exposure to silicon dust, which is ingested by macrophage and causing its damage and release of FGF, resulting in lung fibrosis (silicotic nodules)
* Causes an insidious disease that can progress to respiratory failure. Also, high risk for TB, but no cancer risk
Define Asbestosis
Asbestos (form of silicate) is found in shipyards, insulation and roofing materials, is ingested by macrophages (which forms ferruginous body). There is high risk of cancer & mesothelioma (pleural and peritoneal)
- Can develop 15–20 years after cessation of regular asbestos exposure
- Results in diffuse interstitial fibrosis.
Define ferruginous bodies
Formed by macrophages in an attempt to digest the small asbestos fibers. The fibers are covered by hemosidrin and glycoproteins
* Stain with Prussian blue
Define Berylliosis
caused by exposure to beryllium or its salts. Causes Type IV hypersensitivity with noncaseating granuloma and eventual fibrosis
* Mimics sarcoidosis
Cardiogenic congestion and edema is usually the result of ……
- Left Heart failure, mitral stenosis
- Nephrotic syndrome (volume overload)
- Decrease lymphatic drainage
Non cardiogenic edema is caused by …….
injury to both the capillary endothelium and alveolar epithelium from various causes.
* The lungs are heavy, wet, with accumulation of pink granular precipitate. There is also RBC and hemosidrin containing macrophages
The pulmonary circulation is characterized by …… & ……. to protect …….
low resistance, low pressure
protect the right ventricle from excessive work
What are the causes of primary pulmonary hypertension??
Unknown, but could be due to:
- Small pulmonary emboli
- Hormonal induced vascular hyperactivity
- Immune complex mediated disease
- Diet, medication
What are the causes of secondary pulmonary hypertension??
Increased vascular resistance due to:
- Increase blood flow: ASD, VSD, PDA, or Eisenmenger’s complex (all three combined)
- Hypoxic vasoconstriction
- Elevated left heart pressure: CHF, mitral stenosis, myxoma
- Destruction of pulmonary vessels, COPD
Describe the vascular changes that occur in primary pulmonary hypertension
There is medial hypertrophy, with thickening and fibrosis of intima and adventitia
If a bedridden patient develops dyspnea post surgically, the possible cause is ……
pulmonary embolism
Few pulmonary emboli cause infarction because …..
the presence of collateral circulation
The symptoms of large pulmonary emboli resembles …….
MI symptoms, and it may cause death
The type of infarction in the lung is ……..
red infarction
* Initially, there is hemorrhage and ischemic necrosis. Then it is followed by fibrosis and scar formation
Fat embolism develops after …..
long bone fractures, usually 3 days after
* There is high mortality rate
What are the types of benign pulmonary tumors?
- Hamartomas
- Bronchial adenoma: from the mucus glands
- Leiomyomas: from smooth muscles
- Hemangiomas: often subpleural
- Lipoma: usually endobronchial
- Chondromas: exclusively from bronchial cartilages
Bronchial carcinoid tumors account for ….. of all lung tumors
5%
* It is associated with carcinoid syndrome
What are the types of bronchiogenic carcinoma??
- Adenocarcinoma: 35% of cases, less associated with smoking
- SCC: 25%, high association with smoking (due to metaplasia and dysplasia). Arises from bronchial epithelium, high metastasis rate. Secretes PTH
- Small cell carcinoma: 25%, large soft gray white masses that narrow the bronchi circumferentially. Secretes ADH & ACTH
- Large cell carcinoma: 15%
What is the effect of cigarette smoking on the pulmonary epithelium?
- Loss of cilia
- Basal epithelial hyperplasia
- Nuclear hyperchromatism
Oxidative air pollutants increase the risk of lung cancer. T/F??
False
* Reducing agents (sulfur dioxide) increase
Intrabronchial tumors cause ……
mild cough, partial obstruction (with emphysema), total obstruction (causing postobstructive atelectasis & pneumonia)
Intrathoracic spread of lung tumors may cause …..
- SVC syndrome
- Horner syndrome
- Dysphagia
- Hoarseness (recurrent laryngeal N. involvement)
- Diaphragm paralysis (phrenic N. damage)
- Pancoast tumor: at the lung apex, which causes Horner syndrome and Ulnar nerve pain.
Most common sites of lung tumor metastases are ……
Bone (most common), liver, brain, lymph nodes, adrenals
What is the difference between exudate and transudate?
- Exudate: high protein, high lactate dehydrogenase, low glucose, relatively clear, contains few WBCs, specific gravity greater that 1.02
- Transudate: low protein, low lactate dehydrogenase, straw colored, specific gravity less that 1.01
To diagnose lung cancer, pathologists use ……
sputum cytology, bronchial biopsies, and open biopsies
* For the purpose of staging, bone and lymph node metastases evaluation is a requirement.
What is the causes of hydrothorax?
- CHF
- Renal failure & nephrotic syndrome
- Cirrhosis
* The fluid is transudate
Define Serofibrinous pleuritis
Pleural effusion (exudate) caused by inflammatory disease within the lung (TB, pneumonia, lung infarcts, abscess, bronchiectasis), or systemic diseases (SLE, rheumatoid arthritis)
Define suppurative pleuritis (empyema)
purulent exudate with bacterial or fungal seeding from lung, or through blood/lymph.
* Characterized by yellow-green pus with high WBC content
Pneumothorax is common in patients with ….
emphysema, asthma, TB
Pleural tumor is usually a metastasis from …..
lung, breast
Define malignant mesothelioma
Rare tumor of the parietal or visceral pleura due to asbestos exposure for a long peroid (25 years or more)
* In contrast to bronchogenic tumor, smoking does not increase the risk of malignant mesothelioma
What are the most common causes of laryngitis?
- Lung inflammation
- TB, syphilis, diphtheria
- Mouth and throat inflammation
Laryngeal polyps are associated with …… . Papilloma is ……
- smoking and overuse (usually on the vocal cords)
- Soft neoplasm that bleeds easily, but rarely undergo malignant transformation
- Note that: these benign lesions are either pedunculated or sessile
Most malignant tumors of the larynx are …..
SCC on the vocal cords
- There is hoarseness, hemoptysis, dysphagia & pain
- Risk factors are alcohol, smoking, frequent cord irritation
Treatments for asthma include ……..
Steroids, Beta 2 agonists, epinephrine, albuterol, mast cell stabilizer
