Lung

Obstructive pulmonary disease

Emphysema



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Last staff update: 3 May 2022

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PubMed Search: Lung emphysema[TI] full text[SB]

Akira Yoshikawa, M.D.
Sakda Sathirareuangchai, M.D.
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Cite this page: Yoshikawa A, Bychkov A, Sathirareuangchai S. Emphysema. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/lungnontumoremphysema.html. Accessed December 7th, 2022.
Definition / general
  • Abnormal enlargement of air spaces distal to the terminal bronchioles characterized by destruction of the alveolar septa with little or no fibrosis
Essential features
  • Destruction of acinar structure and airspace enlargement
  • Affects multiple pulmonary functions and causes chronic respiratory symptoms
Terminology
  • By the Global Initiative for Chronic Obstructive Lung Disease (GOLD), an international organization launched by the National Heart, Lung, and Blood Institute, National Institutes of Health, U.S. and the World Health Organization (WHO)
  • Chronic obstructive pulmonary disease (COPD) (Global Initiative for Chronic Obstructive Lung Disease: 2021 GOLD Reports [Accessed 20 December 2021])
    • Common progressive disease that is characterized by persistent respiratory symptoms and usually associated with the prolonged exposure to noxious particles or gases, especially smoking
    • Airflow limitation is caused by a combination of airways disease (chronic bronchitis) and lung parenchymal destruction (emphysema)
  • Major types of emphysema (Lancet 2004;364:709, Int J Chron Obstruct Pulmon Dis 2008;3:193):
    • Centriacinar, centrilobular or proximal acinar emphysema (mostly associated with smoking and COPD)
    • Panacinar or panlobular emphysema
    • Paraseptal or distal acinar emphysema
  • Minor types of emphysema:
    • Combined pulmonary fibrosis and emphysema (CPFE)
    • Interstitial emphysema
    • Bullous emphysema
    • Senile emphysema
    • Irregular emphysema
    • Congenital lobar emphysema
ICD coding
  • ICD-10:
    • J43.1 - panlobular emphysema, panacinar emphysema
    • J43.2 - centrilobular emphysema
    • J43.8 - other emphysema
    • J43.9 - emphysema, unspecified
  • ICD-11:
    • CA21.1 - panlobular emphysema, panacinar emphysema
    • CA21.2 - centrilobular emphysema
    • CA21.Y - other specified emphysema
    • CA21.Z - emphysema, unspecified
Sites
  • Centriacinar emphysema
    • Upper lobe predominant
    • Respiratory bronchioles and surrounding lung parenchyma
  • Panacinar emphysema
    • Lower lobe predominant
    • Entire acinus
  • Paraseptal emphysema
    • Upper lung
    • Distal part of acinus in subpleural area
Pathophysiology
  • Destruction of lung parenchymal tissue due to chronic inflammation
  • Protease mediated destruction of elastin is an important feature (Thorax 2016;71:105)
  • Morphological progression (Int J Chron Obstruct Pulmon Dis 2016;11:2287, Clin Anat 2015;28:227)
    • Increase in size and number of small fenestrae in alveolar walls (pores of Kohn), which leads to loss of elastic recoil
    • Breakdown and merging of fibrovascular trabeculae (framework)
    • Remodeling of acini results in airspace enlargement
Etiology
Diagrams / tables

Images hosted on other servers:

Components of COPD

Classification of emphysema

High resolution CT diagram

Clinical features
  • Dyspnea; chronic, progressive and usually irreversible
  • Chest inflation
  • Combined pulmonary fibrosis and emphysema (CPFE) (Chest 2012;141:222, Eur Respir J 2005;26:586)
    • Coexistence of interstitial fibrosis and emphysema of unknown causes
    • Patients with CPFE have different pulmonary function tests and outcomes compared to patients with pure emphysema or pure fibrosis
  • Interstitial emphysema (Am J Surg Pathol 2014;38:339)
    • Air gains access to the pulmonary interstitium to cause air leak and pneumothorax
    • Common in premature infants
    • Adults: commonly in usual interstitial pneumonia but can occur in any interstitial lung diseases
  • Bullous emphysema
    • Formation of multiple bullae > 1 cm with thin wall
    • Can cause bullae inflation and pneumothorax
  • Senile emphysema
    • Due to age related alteration of acini
  • Irregular emphysema
    • Occurs in relation to scars
  • Congenital lobar emphysema (Pediatr Clin North Am 1994;41:453)
    • Hyperinflation of one or more lobes due to malformation of bronchioles
    • Causes respiratory distress
    • Can be sporadic or caused by autosomal dominant inheritance
Diagnosis
  • Primarily diagnosed by imaging studies with compatible clinical manifestation
  • Rarely diagnosed solely in biopsy specimens
    • More commonly diagnosed in autopsy specimens or as a background finding in resection specimens
Laboratory
  • Screening for alpha-1 antitrypsin deficiency (AATD) is recommended by some experts in all patients with COPD (Chronic Obstr Pulm Dis 2016;3:668)
    • Alpha-1 antitrypsin (AAT) serum level and genotype
Radiology description
  • Xray: overinflation of the lung but it may not be seen in early stages
  • Chest CT: emphysematous regions are represented by low attenuation areas (Eur Respir J 2016;48:216)
Radiology images

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Centriacinar emphysema

Centriacinar emphysema

Panacinar emphysema

Paraseptal (distal acinar) emphysema


Interstitial emphysema

CPFE

AATD

Prognostic factors
Case reports
Treatment
Gross description
  • Hyperinflation or ballooning due to entrapment of the air from airway obstruction
    • Lungs may be overlapping the heart
    • Upper lobes are more involved
  • Centriacinar: sparse empty spaces with pigmentation (anthracosis) corresponding enlarged airspaces
  • Panacinar: airspaces are more or less evenly inflated throughout the secondary lobules
  • Paraseptal: inflated subpleural airspaces with thin walls
  • Bullous emphysema
    • Descriptive term regarding emphysematous lung with visible bullae upon gross examination
    • Bulla: an air filled space of 1 cm in diameter within the lung which has developed because of emphysematous destruction of the lung parenchyma (StatPearls: Bullous Emphysema [Accessed 5 January 2022])
Gross images

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Centriacinar emphysema

Centriacinar emphysema

Panacinar emphysema


Paraseptal (distal acinar) emphysema

Centriacinar versus panacinar emphysema

Cystic formation from alveolar wall destruction

Lung bullae

"Dirty holes" in subtle emphysema


Combined emphysema and fibrosis

Microscopic (histologic) description
  • General findings
    • Airspace enlargement; the size of airspace in the background parenchyma serves as a reference; although exact microscopic criteria have not been established
    • Fragmented alveolar walls
      • If the acinar arrangement is maintained, it is representing pores of Kohn
      • If not, it is representing acinar destruction
    • Mild fibrotic change can be seen
    • Any degrees of inflammation can accompany
    • Subtype is determined with histological landmarks, although exact classification is better appreciated at gross exam:
      • Bronchovascular bundle of terminal bronchiole and arteriole is in the center of acinus
      • Connective tissue septa (secondary lobule of Miller) are the periphery of acinus, which is often ambiguous in less inflamed lung
    • Note: similar appearance can be seen due to inadequate inflation or fixation of specimen
  • Combined pulmonary fibrosis and emphysema (CPFE)
    • Centrilobular emphysema in upper lobes
    • Usual interstitial pneumonia in lower lobes
  • Interstitial emphysema
    • Elongated or angulated spaces in fibrotic interstitium
    • Surrounded by dense fibrosis and lining of multiple giant cells but not epithelium
    • Most commonly around bronchovascular bundles
Microscopic (histologic) images

Contributed by Akira Yoshikawa, M.D.
Normal lung architecture

Normal lung architecture

Peribronchiolar region

Peribronchiolar region

Centriacinar involvement Centriacinar involvement Centriacinar involvement

Centriacinar involvement

Panacinar emphysema

Panacinar emphysema


Paraseptal emphysema

Paraseptal emphysema

Virtual slides

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Severe emphysema

Centriacinar emphysema

Panacinar emphysema

Paraseptal emphysema with fibrosis

Positive stains
  • Elastic stains, such as elastic van Gieson and elastica Masson
Electron microscopy images

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Remodeling of elastin and collagen

Videos

Emphysema histology

Emphysema classification

Sample pathology report
  • Lung, right upper lobe, wedge resection:
    • Squamous cell carcinoma (see comment)
    • Comment: Background lung parenchyma with emphysema, respiratory bronchiolitis and smoking related interstitial fibrosis.
Differential diagnosis
Board review style question #1

What is the most common etiology associated with this alveolar abnormality?

  1. Autoimmune disease
  2. Cigarette smoking
  3. Congenital defect
  4. Infection
  5. Malignancy
Board review style answer #1
B. Cigarette smoking has a strong association with emphysema, particularly centriacinar

Comment Here

Reference: Emphysema
Board review style question #2
Which one of the following lung pathologies can be found in individual with alpha-1 antitrypsin deficiency (AATD)?

  1. Bronchiolitis
  2. Centriacinar emphysema
  3. Interstitial emphysema
  4. Panacinar emphysema
  5. Usual interstitial pneumonia
Board review style answer #2
D. Lung pathologies in AATD patient include panacinar emphysema and bronchiectasis

Comment Here

Reference: Emphysema
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