Objective: To describe a form of interstitial lung disease pathologically characterized by small airway-centered interstitial fibrosis (ACIF).
Methods: We analyzed the clinical, pulmonary functional, radiographic, and histologic characteristics of one ACIF case in Peking Union Medical College Hospital and reviewed 12 cases in literatures.
Results: Clinically, patients presented with chronic cough and progressive dyspnea. Pulmonary function tests showed restrictive ventilatory pattern. Bronchoalveolar lavage showed a mild increase in lymphocytes in most cases. Chest radiography revealed diffuse reticulonodular infiltrates, with thickening of the bronchial walls and surrounding fibrosis. The key finding in histopathology was a distinctive pattern of ACIF centered on membranous and respiratory bronchioles.
Conclusions: ACIF is a disease that do not fit into any known category of interstitial lung disease. Whether it is a unique disease remains to be determined.