Respiratory System: Pathology
Terms
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- Cause of common cold
- Adenovirus
- Croup
-
Acute laryngotracheobronchitis
Acute inflammation of larynx, trachea, and epiglottis
Potentially life-threatening in infants
Harsh cough and inspiratory stridor
Caused by parainfluenza virus, most commonly - Main cause of epiglottitis
-
H. influenza
Can be life-threatening - Nasopharyngeal carcinoma
-
Most common in adults (SE Asia) and children in East Africa
Caused by EBV - Squamous cell carcinoma of the nose
- most frequently occurring malignant nasal tumor
- adenocarcinoma of the nose/throat
- responsible for 5% of all the nose/throat malignancies
- Plasmacytoma
- plasma cell neoplasm that in its extraosseous form, produces tumros in the upper respiratory tract
-
Singer's nodules histology
cause
location
symptoms -
Benign laryngeal polyp
Associated with overuse of the voice and smoking
Localized to true vocal cords
Hoarseness - Laryngeal papilloma
-
In adults: single lesion, can turn malignant
In children: caused by HPV 6 and 11; multiple lesions, recurs after resection -
Squamous cell carcinoma of the larynx
Epidemiology
Presentation -
most common malignant tumor of the larynx
Seen in men older than 40
Associated with smoking and alcoholism (combined)
Present with persistent hoarseness - What is glottic carcinoma?
-
Most common type of laryngeal carcinoma
Has best prognosis - What is supraglottic ad subgglottic carcinoma?
-
less common laryngeal carcinoma
poorer prognosis - Extrinsic asthma
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asthma associated witeh chronic bronchitis, exercise induced, and cold-induced asthma
Begins in adult life
Not assocaited with hx of allergy - clinical Characteristics of asthma
-
Episodic dyspnea and wheezing on expiration
Narrowing of the airways - Histology of asthmatic airways
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Bronchial smooth muscle hypertrophy
Hyperplasia of goblet cells
Thickening and hyalinization of BM
Proliferation of eosinophils
Intrabronchial mucous plugs containing whorl-like accumulations of epithelial cells
Crystalloids of eosinophil-derived proteins - What are Curschmann spirals
- Whorl-like accumulations of epithelial cells seen in asthma
- What are Carcot-Leyden crystals?
- Crystalloids of eosinophil-derived proteins
- Complications of asthma?
-
Superimposed infection
Chronic bronchitiis
Pulmonary emphysema
Status asthmaticus - Definition of chronic bronchitis
- Productive cough lasting 3 consecutive weeks over 3 consecutive years
- Causes of chronic bronchitis
-
Cigarette smoking
pollution
infection
genetics - What can chronic bronchitis lead to?
- cor pulmonale
- Histology of chronic bronchitis
- Hypersecretion of mucus d/t marked hyperplasia of mucus secreting submucosal glands
- What composes a respiratory acinus?
-
respiratory bronchiole
alveolar duct
alveoli - Characteristics of centrolobular emphysema
-
Dilation of respiratory bronchioles
In apex/upper part of pulmonary lobes - Characteristics of panacinar emphysema?
-
Dilation of the entire acinus, starting in the alveoli and alveolar duct, then respiratory bronchiole
Most commonly occurs in the lower basal zones - Characteristics of paraseptal emphysema
-
Alveoli and alveoar ducts are dilated
Localizes subjacent to pleur interlobar septa - Which type of emphysema is associated with alpha-1 anti-trypsin deficiency
- Panacinar emphysema
- What are complications of emphysema
-
Chronic bronchitis
Interstitial emphysema
Rupture of a surface bleb with resulting pneumothorax - What is interstitial emphysema
- air escapes into the interstitial tissue of chest from a tear in the airways
- Pathogenesis of emphysema?
-
Cigarette smoke causes recruitment of neutrophils and macrophages, which release elastase
Elastase destroys elastin unless neutralized alpha-1 anti-trypsin
Cigarettes inactivate alpha-1 anti-trypsin - What is the PiZ allele
- structural alteration in alpha-1 anti-trypsin, which interferes with the hepatic secretion of it
- What is alpha-1 anti-trypsin deficiency associated with?
-
panacinar emphysema
hepatic cirrhosis
cholestasis
hepatocellular carcinoma in 1-2% of homozygous adults - What is bronchiectasis?
- Permanent abnormal bronchial dilation
- What causes bronchiectasis
- Chronic infection wiht inflammation and necrosis of the bronchial wall
- What are predisposing factors for bronchiectasis?
-
Bronchial obstruction (often by tumor)
CF
necrotizing bacterial, viral or fungal pneumonai
RA
GVHD
chronic sinusitis with post nasal drip
Kartagener syndrome - Manifestations of Kartagener syndrome
-
sinusitis
bronchiectasis
situs inversus (left-right reversal of thoracic viscera)
hearing loss
immotile sperm - Cause of Kartagener syndrome
- structural defect in dynein arms, impairing ciliary activity
- Where in the respiratory tract does bronchiectasis most commonly appear?
- Lower lobes of both lungs
- Manifestations of bronchiectasis
-
copious purulent sputum
hemoptysis
recurrent pulmonary infection --> lung abscess - Complications of bronchiectasis
-
cor pulmonale
metastatic abscess
systemic amyloidosis - Characteristics of interstitial lung diseases
-
interstitial accumulations of cells or noncellular material within the alveolar walls that restrict expansion and interfere with gaseous exchange
(increased A-a gradient... V/Q mismatch) - EXamples of interstitial lung disease
-
ARDS
Neonatal respiratory distress syndrome
Pneumoconiosis
Sarcoidosis
Idiopathic pulmonary fibrosis
SLE
Scleroderma
Goodpasture syndroem
Wegener granulomatosis - How does pulmonary fibrosis lead to cardiac failure?
- Pulmonary fibrosis --> repeated cycles of cellular injury --> abnormal wound healing b/c of excessive fibroblast proliferation --> cor pulmonale, pulmonary insufficiency and cardiac failure
- Pathogenesis of ARDS?
- diffuse alveolar damage --> increased capillary permeability --> leakage of protein rich fluid (exudate) into alveoli
- Histology of ARDS
- intra-alveolar hyaline membrane made of fibrin and cellular debris
- Clinical result of ARDS
- impairment of respiratory gas exchange with severe hypoxia
- Causes of ARDS
-
toxic agents
shock
sepsis
trauma
uremia
aspiration of gastric contents
acute pancreatitis
O2 toxicity
OD of heroin or bleomycin
SARS - Relationship between SARS and ARDS
- SARS (a coronavirus) destroys type II pnemocytes --> diffuse alveolar damage
- Things that influence ARDS
-
Neutrophils that release substances toxic to alveolar wall
Activation of coagulation cascade
O2 toxicity from free radicals - Causes for neonatal respiratory distress syndrome
-
Surfactant deficiency, from premature birth/premature lungs
seen in diabetic mom, poor glucose control, c-section - Clinical manifestations of neonatal respiratory distress syndrome
-
Dyspnea
Cyanosis
Tachypnea - Component of surfactant
- dipalmitoyl lecithin
- Way to determine fetal pulmonary maturity
-
measure ratio of surfactant lecithin to sphingomyelin in amniotic fluid
[Lecithin] increases from 33rd week of pregnancy, while sphingomyelin remains stable
L:S 2:1 or higher = pulmonary maturity - Factors predisposing to neonatal respiratory distress syndrome
-
Prematurity
Materal DM
C-section - Pathologic findings of neonatal RDS
-
lungs are heavier than normal
Areas of atelectasis alternating with dilated alveoli/alveolar ducts
Small pulmonary BV are engorged witeh blood, with leakage of blood products into alveoli
Formation of hyaline membranes within alveoli - Components of hyaline membranes in neonatal RDS
- fibrin and cellular debris
- Complications/associated conditions with neonatal RDS
-
Bronchopulmonary dysplasia
PDA
Intraventricular brain hemorrhage
Necrotizing enterocloitis (inflammation of large and small intestines) - Morphology of necrotizing enterocolitis
-
mucosal edema
hemorrhage
necrosis of terminal ileum and entire gut - Components of coal dust
- carbon and silica
- markings of simple coal workers' pneumoconiosis
- Coal macules around bronchioles
- What can progresive massive fibrosis from coal workers' pneumoconiosis lead to?
-
bronchiectasis
pulmonary HTN
death from respiratory failure
cor pulmonale - Careers associated with silicosis
-
miners
glass manufacturers
stone cutters - dangers of silicotic nodules
- enlarge and obstruct airways and BV
- risks associated with silicosis
-
increased TB risk
can also be concurrent (silicotuberculosis) - Pathogenesis of asbestosis
-
asbestos fibers are taken up by alveolar macrophages
fibroblast-stimulating GF by macrophages likely released --> diffuse interstitial fibrosis in lower lobes - Ferruginous bodies
-
seen in asbestosis
yellow-brown rod shaped bodies with clubbed ends that stain for Prussian blue - Complications of asbestosis
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bronchogenic carcinoma
malignant mesothelioma - Pathologic changes associated with sarcoidosis
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interstitial lung disease
enlarged hilar lymph nodes
anterior uveitis
erythema nodosum of skin
polyarthritis - Immunologic phenomena associated with sarcoidosis
-
reduced sensitivity to skin test antigens
polyclonal hyperglobulinemia - Clinical abnormalities seen with sarcoidosis
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bilateral hilar lymphadenopathy
interstitial lung disease manifest as diffuse reticular densities - Lab findings associated with sarcoidosis
-
hypercalcemia
hypercalciuria
hypergammaglobulinemia
increased ACE - Way to make definitive dx of sarcoidosis
- biospy showing non-casseating granuloma
- Progression of idiopathic pulmonary fibrosis
-
chronic inflammation and fibrosis of alveolar wall
begins with alveolitis --> ibrosis --> distorted fibrotic lung filled with cystic spaces - Honeycomb lung
- typical of idiopathic pulmonary fibrosis
- Prognosis for idiopathic pulmonary fibrosis
-
poor
death often within 5 yrs - morphologic changs of eosinophilic granuloma
-
histiocytic cells closely related ot Langerhans cells of skin
have cytoplasmic inclusions (Birbeck granules) resembling tennis rackets
Prominent monocytes-macrophages, lymphocytes, and eosinophils - Location of eosinophilic granulomata
- lung or bony sites (i.e. ribs)