DIFFUSE PANBRONCHIOLITIS - HISTOLOGIC DIAGNOSIS IN UNSUSPECTED CASES INVOLVING NORTH-AMERICAN RESIDENTS OF ASIAN DESCENT

Objective.-To study and report two cases of diffuse panbronchiolitis i n patients of Asian ancestry residing in the United States and to revi ew the literature pertaining to this disease. Design.-Diffuse panbronc hiolitis is a progressive interstitial pneumonitis occurring primarily in Japan. Rare cases are now being identified in Europe and North Ame rica. Patients often have a history of sinusitis, present with dyspnea on exertion, and show a restrictive pattern on pulmonary function tes ts. The clinical, radiologic, and pathologic features of two cases of the disease received for consultation at the Armed Forces Institute of Pathology, Washington, DC, are reported with a review of the literatu re. Results.-Chest radiographs revealed bilateral small nodular opacit ies with ill-defined borders. High-resolution computed tomography demo nstrated the abnormalities to have a centrilobular distribution. Histo logically, there was transmural chronic inflammation centered on the t erminal bronchioles and an interstitial infiltrate of foamy macrophage s. Conclusion.-Diffuse panbronchiolitis may be mistaken for other more common small airway diseases and may be underrecognized in Western na tions. The immigration of Asians and sporadic case reports involving n on-Asians make recognition of this disease entity important, as the im plications for therapy are different than that of other small airway d iseases.