Atypical pneumocytes appearing in interstitial pneumonia

Abstract

Objective: To avoid misinterpreting interstitial pneumonia(IP)as adenocarcinoma, we examined the cytological features of atypical pneumocytes in IP.
Study Design: We examined cytological specimens from 10 patients with IP without cancer, which showed atypical pneumocytes in brushing cytology, bronchial washing, or bronchoalveolar lavage fluid and compared these cytologically with simultaneously obtained transbronchial lung biopsy (TBLB) specimens.
Result: All 10 showed an inflammatory background. Pneumocytes showed distinct nucleoli, coarse chromatin without an increase in quantity, thickly distinct cell borider, vacuolated cytoplasm, and constituted small cluster form. The most distinct cytological findings were collagen globules surrounded by pneumocytes and Mallory bodies in cytoplasm.
Conclusion: TBLB or surgery may acutely exacerbate IP. To avoid repetitious procedures for the detection of malignancy, it is important to consider IP when collagen globules or Mallory bodies are seen in cytological specimens even if cell atypia suggests adenocarcinoma.