Extensive squamous metaplasia with cytologic atypia in diffuse alveolar damage mimicking squamous cell carcinoma: a report of 2 cases.

Squamous metaplasia in the setting of diffuse alveolar damage, a form of acute lung injury, in rare cases can be very extensive with cytologic atypia, mimicking squamous cell carcinoma. We describe 2 such cases that posed diagnostic difficulty in the evaluation of biopsy specimens. These cases demonstrate that histologic findings must be correlated with clinical and radiologic information to avoid a misdiagnosis of malignancy. Copyright 2002, Elsevier Science (USA). All rights reserved.