Case 17

Section 1

Look at images 1 and 2.

Image 1

1. What are the abnormalities?

2. What is the distribution?




Image 2


Section 2

Image 1


Find 2 areas of focal consolidation (1 peripheral) in the left lung and one in the right lung.

Find a large centrilobular nodule in the left lung.

Find a collection of ground-glass nodules in the left lung.

Find an area of consolidation against the minor fissure in the right lung.

Image 2

Find an area of bronchovascular consolidation in the right lung and a band-like area of bronchovascular consolidation in the left lung.

Find a peripheral consolidation in the left lung.

Section 3

Histologic Features

This overview of an open biopsy shows a bronchiole cut longitudinally. Branching from it are several airways surrounded by lobular alveolar infiltrates, some of which are confluent.

Find the longitudinally-cut bronchiole.

Find two separate alveolar infiltrates with bronchioles at the center.

Find an example of peribronchiolar lobular infiltrates that have become confluent.


A bronchiole and adjacent alveolar spaces are partly filled with loose connective tissue all of the same age (temporally uniform). Note that more distant alveoli are normal, but sometimes an entire lobule can be involved.

What is this type of connective tissue called?


Find the bronchiole.

Find the accompanying pulmonary artery.

Find 3 examples of loose connective tissue in alveolar spaces.


Differential diagnosis of subacute/chronic consolidation and ground-glass on HRCT: Bronchiolitis obliterans organizing pneumonia, chronic eosinophilic pneumonia, Churg-Strauss syndrome, desquamative interstitial pneumonia, nonspecific interstitial pneumonia, chronic hypersensitivity pneumonia, mycoplasma pneumonia, lymphoma, lipoid pneumonia.

Histologic differential diagnosis: Causes of this pattern include bacterial and viral infections, multiple different drugs, aspiration, radiation, transplantation (bone marrow and lung), collagen vascular diseases, and inflammatory diseases (ulcerative colitis, Crohn's disease, and others). If the cause is not known, the pattern is referred to as idiopathic BOOP or cryptogenic organizing pneumonia [1]. A focal variant has been described. Fibrosis on the biopsy had been associated with a poor prognosis.

Diagnosis: Bronchiolitis obliterans organizing pneumonia

Diagnostic features of bronchiolitis obliterans organizing pneumonia on HRCT

Comment: The HRCT is useful for determining the site to biopsy in this patchy disease.


1. Cordier J-F. Cryptogenic organizing pneumonitis. Bronchiolitis obliterans organizing pneumonia. Clin Chest Med 1993; 14:677-692.



Table of Contents






























Focal consolidation






























Focal, peripheral consolidation
































Centrilobular ground-glass nodules
































Large centrilobular nodule
































Consolidation against the minor fissure. The minor fissure is the homogeneous area that lies central to the consolidation.































Bronchovascular consolidation






























Focal, peripheral consolidation



























1. a) Irregular areas of consolidation some with air bronchograms
b) Areas of ground-glass opacity
c) Regions of ground-glass centrilobular nodules, all in a background of normal lung

2. Patchy, with a tendency to be subpleural. The smallest lesions appear to be lobular. In addition, note band-like regions of consolidation extending from the left hilum into the lower lobe in a peribronchovascular distribution.































Bronchiole cut longitudinally





























Lobular infiltrate with bronchiole at center































Confluent lobular infiltrates



















































Granulation tissue composed of fibroblasts, loose matrix, inflammatory cells, and capillaries





























































Pulmonary artery

































Loose connective tissue (granulation tissue)