Lung-nontumor
Chronic obstructive pulmonary disease (COPD)
Emphysema

Author: Akira Yoshikawa, M.D. (see Authors page)
Editor: Andrey Bychkov, M.D., Ph.D.

Revised: 30 December 2016, last major update December 2016

Copyright: (c) 2003-2016, PathologyOutlines.com, Inc.

PubMed Search: emphysema[title]
Cite this page: Emphysema. PathologyOutlines.com website. http://pathologyoutlines.com/topic/lungnontumoremphysema.html. Accessed April 25th, 2017.
Definition / General
  • Pulmonary emphysema is defined as permanent abnormal enlargement of air spaces distal to the terminal bronchioles with destruction of the alveolar septa with little or no fibrosis
  • In a broad sense, emphysema refers to the condition when air is abnormally introduced and trapped in the tissue; it can occur in any part of body such as subcutaneous soft tissue, mediastinum, epidural area and solid organs
Essential Features
  • Destruction of acinar structure and airspace enlargement, especially due to cigarette smoking
  • Affects multiple pulmonary functions and causes chronic respiratory symptoms
Terminology
Epidemiology
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
Clinical Features
  • Dyspnea; chronic, progressive and usually irreversible
  • Chest inflation
  • 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 than 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
Radiology Description
  • X ray: 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)
Prognostic Factors
  • Based on exacerbation risk of COPD (GOLD)
    • GOLD score 3 or 4 (severe or very severe airflow limitation)
    • Previous history of exacerbation and hospitalization
    • Faster loss of forced expiratory volume in 1 sec
    • COPD assessment test score ≥ 10 (CATest, Eur Respir J 2009;34:648)
Case Reports
Treatment
  • Based on treatment of COPD (GOLD)
    • Smoking cessation
    • Medications: bronchodilators, antimuscarinic drugs, steroids, etc.
    • Ventilatory support
    • Surgical interventions: lung volume reduction surgery, bullectomy, lung transplant
    • Augmentation therapy for alpha-1-antitrypsin deficiency (Eur Respir Rev 2015;24:46)
Clinical Images

Images hosted on other servers:

Case of alpha-1-antitrypsin deficiency

Centriacinar emphysema


Panacinar emphysema

Paraseptal emphysema

CPFE

Gross Description
  • 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
Gross Images

Images hosted on other servers:

Centriacinar emphysema


Panacinar emphysema

Paraseptal (distal acinar) emphysema


Lung with cystic spaces due to destruction of airsac walls

Dilated airspaces with emphysema

Large bullae on surface of lungs

Centrilobular
emphysema with
focally appearing
holes
Micro Description
  • General findings
    • Airspace enlargement; the size of airspace in the background parenchyma will be a good reference
    • Fragmented alveolar walls
      • If the acinar arrangement is well remained, 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
    • The subtype is determined with histological landmarks:
      • Bronchovascular bundle of terminal bronchiole and arteriole is in the center of acinus
      • Connective tissue septa ("secondary lobule of Millar") 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
  • 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
Micro Images

Images hosted on PathOut server:

Contributed by Dr. Yoshikawa, Nagasaki University School of Medicine (Japan):

Nonemphysematous lung; right: peribronchiolar region

Centriacinar emphysema; right: with focal fibrotic change


Panacinar emphysema

Paraseptal emphysema with focal fibrotic change

Interstitial emphysema; right: honeycomb is also seen



Images hosted on other servers:

Subtypes of pulmonary emphysema

Progression model of pulmonary emphysema

Centriacinar emphysema

Virtual Slides

Images hosted on other servers:

Centriacinar emphysema in late stage

Severe emphysema

Electron Microscopy Images

Images hosted on other servers:

Remodeling of elastin and collagen

Videos


Histopathology Lung - Emphysema
Differential Diagnosis