Other Features of UIP

Epithelial Metaplasias--Bronchiolization

Epithelial metaplasias occur as part of the inflammatory process in UIP. When there is spread of ciliated respiratory epithelium or goblet cells into air spaces with fibrotic walls adjacent to airways, the term bronchiolization is used. In the photo, note that the bronchiole (B) is surrounded by thick-walled spaces lined by respiratory epithelium--bronchiolization.

Atypical Epithelial Hyperplasia

BAL fluid from patients with interstitial lung disease may contain cells that are suspicious for malignancy. These cells originate from atypical metaplastic epithelium as shown here. The metaplastic cells, which are a part of the inflammatory process, have hyperchromatic nuclei and increased nuclear/cytoplasmic ratios. The atypia shown here was not considered to be neoplastic. Clinical and CT findings are important in deciding whether to pursue a diagnosis of cancer in a patient with UIP and atypical cells in lavage fluid [1].


1. Biyoudi-Vouenze R, Tazi A, Hance A, Chastre J, Basset F, Soler P. Abnormal epithelial cells recovered by bronchoalveolar lavage: are they malignant? Am Rev Respir Dis 1990; 142:686-690.

Clinical summary Discussion

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