Distinctive radiographic and histologic features characterize this airway disease, which was first described in adults in Japan, but has now been reported in the U.S. A cellular inflammation may progress to fibrosis (bronchiolitis obliterans/constrictive bronchiolitis) and proximal bronchiectasis. Treatment in the early stages with macrolides can ameliorate symptoms and improve survival.

In the early phase of the disease, small centrilobular nodules seen on HRCT represent a chronic inflammatory infiltrate in the walls and surrounding alveolar interstitium of terminal bronchioles, respiratory bronchioles, and alveolar ducts. Disease does not predominate in membranous bronchioles as in the other types of bronchiolitis discussed here.


Figure 1. Histologically, distinctive foamy macrophages are present among the lymphocytes as shown here in the interstitium of alveolar walls surrounding a narrowed airway (not shown).

Note the foamy macrophages in the interstitial infiltrate.

Figure 2

At higher magnification, the lipid-laden foam cells are better seen.

Photos provided by Dr. Kirk Jones.


1. Nishimura K, Kitaichi M, Izumi T, Itoh H. Diffuse panbronchiolitis: correlation of high-resolution CT and pathologic findings. Radiology 1992; 184:779-785. Abstract

2. Krishnan P, Thachil R, Gillego V. Diffuse panbronchiolitis. A treatable sinobronchial disease in need of recognition in the United States. Chest 2002; 121:659-661. Abstract

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