CRYPTOGENIC CONSTRICTIVE BRONCHIOLITIS - A CLINICOPATHOLOGICAL STUDY

Four women with a chronic respiratory illness characterized by chronic cough, dyspnea, mild to severe physiologic abnormalities, relatively normal chest radiographs, and lack of response to bronchodilators or p rednisone were identified and prospectively evaluated. Constrictive br onchiolitis, defined as concentric narrowing of the bronchiolar lumen, mural scarring, smooth muscle hyperplasia, and mucus stasis, was the major histologic finding on open lung biopsy in all cases. Each presen ted with an illness clinically distinct from asthma, connective tissue disorders, occupational or environmental lung disease, bronchiectasis , diffuse panbronchiolitis, cystic fibrosis, and emphysema. None of th e patients smoked cigarettes. None had clinical evidence of a recent v iral lower respiratory tract infection. The physical examinations were normal except for rales heard on chest examination in two patients. C hest radiographs showed increased bronchovascular markings in three pa tients. Lung function was normal in one patient, two of the patients h ad a reduced diffusing capacity associated with moderate hypoxemia and an obstructive ventilatory defect, and one patient exhibited a mixtur e of restrictive and obstructive defects. None have experienced signif icant progression of their disease over 1 to 5 yr of follow-up. Howeve r, complete return to normal function did not occur. We hypothesize th at patients with the constellation of findings described represent a d istinct and definable clinicopathologic entity and further clarifies t he spectrum of ''small airways disease.'' Establishing the diagnosis a ppears important for prognostic and possibly therapeutic reasons.