Respiratory Pathology Quiz

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Questions and Answers

What is the primary characteristic of bronchiectasis?

Temporary dilation of bronchi

Obstruction of airways due to mucus

Altered central blood flow

Permanent dilation of bronchi and bronchioles (correct)

Which of the following conditions is NOT a predisposing factor for bronchiectasis?

Chronic GVHD

Postinfectious conditions

Cystic fibrosis

Acute respiratory distress syndrome (correct)

What dysfunction is most commonly associated with primary ciliary dyskinesia?

Overactive cilia leading to excess mucus clearance

Immotile cilia due to dynein arm mutations (correct)

Excessively mobile cilia causing lung damage

Abnormal cilia with improved airflow

Which imaging method is most effective for visualizing bronchiectasis?

CT scan Signup and view all the answers

What is a common consequence of impaired ciliary function in conditions like cystic fibrosis?

Retention of secretions and recurrent infections Signup and view all the answers

In bronchiectasis, what causes permanent dilation of the bronchi and bronchioles?

Destruction of smooth muscle and elastic tissue Signup and view all the answers

What condition is associated with situs inversus in addition to bronchiectasis?

Kartagener syndrome Signup and view all the answers

Which of the following is a common feature observed in patients with cystic fibrosis?

Widespread bronchiectasis Signup and view all the answers

Which type of chronic bronchitis is characterized by a productive cough without airflow obstruction?

Simple chronic bronchitis Signup and view all the answers

What is the primary cause of chronic bronchitis?

Cigarette smoking Signup and view all the answers

What does a Reid index greater than 0.5 indicate?

Chronic bronchitis severity Signup and view all the answers

Which histological feature is NOT associated with bronchiectasis?

Hyperplasia of goblet cells Signup and view all the answers

Which histological change is typical of chronic bronchitis?

Goblet cell prominence Signup and view all the answers

What is the classic biochemical abnormality observed in cystic fibrosis?

High sodium chloride levels in sweat Signup and view all the answers

Which symptom is least likely associated with asthma?

Hemoptysis Signup and view all the answers

Which factor is least likely to contribute to the pathogenesis of chronic bronchitis?

Immunologic reactions Signup and view all the answers

Which of the following complications is NOT typically associated with cystic fibrosis?

Renal failure Signup and view all the answers

In chronic asthmatic bronchitis, what occurs alongside hyperreactive airways?

Inflammation of airway epithelium Signup and view all the answers

What primary defect is responsible for the symptoms of cystic fibrosis?

Abnormal function of the CFTR gene Signup and view all the answers

Which mechanism contributes to the recurrent pulmonary infections seen in cystic fibrosis?

Dehydrated mucus layer leading to mucous plugging Signup and view all the answers

What does chronic inflammation in chronic bronchitis primarily lead to?

Mucus hypersecretion Signup and view all the answers

In the context of bronchiectasis, which pathogen is most commonly associated with chronic infections?

Staphylococcus aureus Signup and view all the answers

How does cystic fibrosis primarily affect the pancreas?

Causing atrophy and fibrosis of the exocrine glands Signup and view all the answers

What role does the CFTR protein play in cystic fibrosis pathogenesis?

Facilitates chloride ion transport Signup and view all the answers

Study Notes

Papanicolaou Stain

Reddish core with a fuzzy margin
Cells attached secondarily
Arrow points at a macrophage

Charcot-Leyden Crystals

Eosinophils

Bronchiectasis

Permanent dilation of bronchi and bronchioles
Destruction of smooth muscle and supporting elastic tissue
Results from or is associated with chronic necrotizing infections
Not a primary disorder

Conditions Predisposing to Bronchiectasis

Congenital or hereditary conditions:
- Cystic fibrosis
- 1° ciliary dyskinesia (immotile cilia syndrome/Kartagener syndrome)
- Immunodeficiency states associated with recurrent bacterial infections (i.e., immunoglobulin deficiencies)
Postinfectious conditions:
- Necrotizing bacterial pneumonias (especially with Staph aureus, Klebsiella, or TB in endemic regions)
Bronchial obstruction due to tumor, foreign bodies
Other conditions: Rheumatoid arthritis, SLE, IBD, chronic GVHD

Pathogenesis of Bronchiectasis

Cases due to nonspecific obstruction and infection:
- Both are necessary for full-blown lesions
- Either can be the initiating factor
Normal clearing mechanisms are impaired:
- Most readily apparent in cystic fibrosis
  - Thick viscid mucus obstructs airways and predisposes to infections
Primary ciliary dyskinesia (immotile cilia syndrome):
- Autosomal recessive/variable penetrance
- Defects in ciliary motor proteins (dynein arm mutations)
- Kartagener syndrome: situs inversus, bronchiectasis, sinusitis
- Bronchiectasis
- Sterility in males: sperm dysmotility
Poorly functioning cilia: Retention of secretions --> recurrent infections --> bronchiectasis

Immotile Cilia Syndrome

Normal dynein arms
Immotile cilia syndrome

Bronchiectasis: CT Scan and Gross Specimen

Dilated airways on the CT scan in longitudinal section (arrowhead) and cross section (arrow)
Cut surface of lung with distended peripheral bronchi filled with mucopurulent secretions (white arrow) in cystic fibrosis

Bronchiectasis: Gross

Bronchiectasis tends to be localized with disease processes
Widespread bronchiectasis is typical in patients with cystic fibrosis

Bronchiectasis: Histology

Desquamation of surface epithelium with ulceration
Destruction of cartilage and smooth muscle
Dilatation of airways
Chronic inflammation and fibrosis of wall
Intraluminal purulent material

Cystic Fibrosis Pathogenesis

Disorder of epithelial ion transport affecting fluid secretion in exocrine glands and epithelial linings of the respiratory tract, GI tract, and reproductive tract
Abnormally viscid mucous secretions --> airway and the pancreatic duct blockages
- Leading to recurrent and chronic pulmonary infections and pancreatic insufficiency
Most common (incidence 1:2500 live births) lethal genetic disease in whites (carrier freq 1:20)
Classic biochemical abnormality: high sodium chloride level in sweat (sweat chloride test)
Primary defect is reduced production (or abnormal function) of an epithelial chloride channel protein encoded by the CF transmembrane conductance regulator (CFTR) gene
- In sweat duct, result is increased sodium and chloride in sweat
- In epithelium of respiratory and GI tract, decreased chloride secretion with increased sodium and water reabsorption in airways results in dehydrated mucus layer, defective mucociliary action, and mucous plugging
Cystic fibrosis affects several organs:
- Pancreas: Mild to most severe
  - Exocrine gland atrophy and fibrosis
  - Impaired fat absorption
  - Vitamin A deficiency
- Small intestine: Mucus plugs --> meconium ileus
- Pulmonary: Thick viscid mucous of submucosal glands --> sinusitis, mucous plugging of bronchioles --> bronchiectasis --> abscesses
  - Staph aureus, Hemophilus influenzae, and Pseudomonas aeruginosa are the most common organisms with Burkholderia cepacia (formerly Pseudomonas cepacia) increasing

Chronic Bronchitis Types

Simple chronic bronchitis: Productive cough but no physiologic evidence of airflow obstruction
Chronic asthmatic bronchitis: Hyperreactive airways with intermittent bronchospasm and wheezing
Obstructive chronic bronchitis: Develop chronic airflow obstruction
- Usually have associated emphysema

Pathogenesis of Chronic Bronchitis

Hallmark is hypersecretion of mucus beginning in large airways
Most important cause is cigarette smoking, followed by other environmental pollutants
Histologic findings:
- Mucus gland hyperplasia: Increased size of glands
  - Reid index = ratio of thickness of mucous gland layer to the thickness of the wall between the epithelium and the cartilage (NL = 0.4)
- Goblet cell metaplasia: Often seen
- Inflammatory infiltration of bronchiolar walls: Lymphocytes, macrophages, neutrophils, no eosinophils
- Fibrosis of the bronchiolar wall: Older patients
- May see squamous metaplasia or dysplasia: Especially with smoking

Evolution of Chronic Bronchitis and Emphysema

Both chronic bronchitis and emphysema can result from different pathways
Either one can predominate

Chronic Bronchitis: Histopathology

Chronic inflammation

Reid Index

Ratio of thickness of submucosal mucus gland layer to thickness of bronchial wall between epithelium and cartilage
Normally = 0.4 or less
Increased (>0.5) in chronic bronchitis proportionally to the duration and severity of disease

Asthma

A chronic disorder of the airways
Usually an immunologic reaction marked by:
- Episodic bronchoconstriction due to increased airway sensitivity to varied stimuli
- Inflammation of bronchial walls
- Increased mucus secretion
Presents with recurrent episodes of wheezing, breathlessness, chest tightness, and cough, especially at night and/or in the early morning
Symptoms are usually associated with:
- Exposure to allergens (pollen, dust mites, animal dander, molds)
- Viral infections (respiratory syncytial virus, rhinovirus)
- Irritants (cigarette smoke, air pollution, cold air, exercise)
- Drugs (aspirin, NSAIDs)

Asthma - Diagnosis

Clinical history and examination: History of recurrent wheezing and shortness of breath
Spirometry: To assess airflow obstruction
Peak expiratory flow rate: Measures the maximum speed of air that can be forcibly exhaled
Methacholine challenge test: Used to assess airway hyperresponsiveness
Allergy testing: Skin prick test, blood tests
Chest x-ray: To rule out other lung diseases
Blood tests: To measure eosinophil count and other inflammatory markers

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Description

Test your knowledge on respiratory pathology, focusing on Papanicolaou stain, Bronchiectasis, and related conditions. Explore details about the characteristics, predisposing factors, and pathogenesis of common respiratory diseases.