ABSTRACT
Bronchiolitis obliterans (BO) is a fibrotic lung disease involving the small conducting
airways. BO may be classified by etiology and underlying disease or, more commonly,
by histopathological pattern. The two major histopathological categories are (1) BO
organizing pneumonia (BOOP) and proliferative bronchiolitis and (2) constrictive bronchiolitis.
The former is often idiopathic in nature and may also be associated with connective
tissue diseases and inhalation injury. Characteristic findings on chest imaging include
alveolar infiltrates and ground glass opacities and pulmonary function tests (PFTs)
usually reveal restrictive dysfunction. Constrictive bronchiolitis is associated with
organ transplantation, infections, connective tissue diseases, inhalation injury,
and drugs and may also have an idiopathic origin. The radiographic characteristic
is a mosaic pattern on high-resolution computed tomography (HRCT) and PFTs most often
reveal obstructive dysfunction. This article will attempt to review constrictive BO,
including histopathology, clinical presentation, radiographic appearance, and physiological
findings, for both idiopathic diseases, as well as specific clinical-associated entities.
KEYWORD
Bronchiolitis obliterans - constrictive bronchiolitis - lung transplantation - bone
marrow transplantation - panbronchiolitis