AAH is proliferative lesion of atypical epithelial cell along the alveolar septa &is commonly multifocal, and may explain multicentricity that is observed with some adenocarcinomas.

• AAH是一种非典型的上皮细胞增殖性的损害，分布于肺泡隔，通常是多病灶的，也解释了部分腺癌多中心的原因。