PREVALENCE OF PULMONARY ATYPICAL ALVEOLAR CELL HYPERPLASIA IN AN AUTOPSY POPULATION - A STUDY OF 100 CASES

A precursor lesion of pulmonary adenocarcinoma has not been clearly de fined. Previous studies suggested that atypical alveolar cell hyperpla sia (AACH) might represent such a precursor lesion. Most previous stud ies showed an association between AACH and adenocarcinoma in surgical resection specimens. In this study, we searched for the prevalence of AACH and nonatypical alveolar cell hyperplasia (AGH) in a general auto psy population. Cases in which there was clinical or anatomic evidence of pulmonary neoplasia were excluded from the study. In the 100 conse cutive autopsies examined, we found four cases of ACH and two cases of AACH. The two AACH lesions showed cytologic atypia and stained positi vely for p53 and c-erb-2. These findings suggest a possible role for A ACH as a precursor lesion of adenocarcinoma of the lung.