Case 21

Section 1

Clinical history: A 68-year-old woman developed a chronic, non-productive cough following the "flu" 4 months before presentation. Severe shortness of breath with mild exercise did not respond to a 10-day course of doxycycline. After a lung biopsy, she was treated with prednisone.

Look at image 1.

Image 1

What is the abnormality?

What is its distribution?


Section 2

Image 1

Find examples of fine and coarse reticular change in both lungs. Note that there is ground-glass opacity in the same location.


Image 2

Post-therapy HRCT

After prednisone therapy, most of the reticular changes and ground-glass opacity disappeared. Dyspnea vanished, and there was an increase in diffusing capacity.

Section 3

Histology of Reticular Change and Ground-glass Opacity

A biopsy from this patient shows a patchy, chronic, intralobular interstitial inflammatory infiltrate. Although there are some interstitial fibroblasts, there is little collagenous scar. Alveolar collapse has caused minor enlargement of a few air spaces.

The patchiness and cellularity with little fibrosis or architectural distortion produce the reticular and ground-glass changes on HRCT.

At higher magnification, two bronchioles are embedded in an inflamed interstitium that thickens intervening alveolar walls. There is mild type II cell hyperplasia, and a few collections of alveolar macrophages are present.

Find and outline two bronchioles. These are defined by smooth muscle in the walls. The accompanying arteries are not seen.

Find two clusters of alveolar macrophages.



Differential diagnosis of ground-glass opacity and reticular change on HRCT: Non-specific interstitial pneumonia, desquamative interstitial pneumonia, acute interstitial pneumonia, bronchiolitis obliterans organizing pneumonia, chronic eosinophilic pneumonia, and Churg-Strauss syndrome. Ground-glass opacity with some consolidation can be seen with usual interstitial pneumonia, but is atypical.

Diagnosis: Non-specific interstitial pneumonia

Histologic differential diagnosis: Collagen vascular disease, hypersensitivity pneumonia, drug reaction, resolving acute lung injury, infection (AIDS), usual interstitial pneumonia (non-representative biopsy), and idiopathic non-specific interstitial pneumonia [1]

Diagnostic features of non-specific interstitial pneumonia on HRCT [2]


1. Katzenstein AA, Myers JL. Idiopathic pulmonary fibrosis. Clinical relevance of pathologic classification. Am J Respir Crit Care Med. 1998; 157:1301-1315.

2. Park J, Lee K, Kim J, Park C, Suh Y, Choi D, Kim K. Nonspecific interstitial pneumonia with fibrosis: radiographic and CT findings in seven patients. Radiology 1995; 195:645-648.



Table of Contents































1. Reticular change and ground-glass opacity

2. Predominantly peripheral

































Reticular change. The posterior reticular changes are coarser than the anterior ones.































































Alveolar macrophages