title: Lung adenocarcinoma with bronchioloalveolar carcinoma component is frequently associated with foci of high-grade atypical adenomatous hyperplasia.
abstract: We assessed the occurrence of atypical adenomatous hyperplasia (AAH) in whole lung lobes with primary cancer lesions. Following surgical resection, tissue specimens were sliced to a thickness of 4 mm (3,641 specimens from 61 cases; mean = 59.7 specimens per case). A total of 119 AAH foci were found and an association was evident in 25 (57%) of 44 adenocarcinomas, 3 (30%) of 10 squamous cell carcinomas, and 2 (29%) of 7 other lung cancers. Histologic evaluation showed that 108 AAH foci were categorized as low-grade and the other 11 as high-grade AAH. These 11 foci of high-grade AAH were present in 7 patients with adenocarcinoma, and in 1 patient there was a synchronous double primary lung adenocarcinoma. High-grade AAH was closely associated with bronchioloalveolar carcinoma (BAC) type adenocarcinoma, and low-grade AAH with non-BAC adenocarcinoma. The mean +/- SD Ki-67 labeling index in high-grade AAH (3.5%+/-2.9%) was significantly higher than for the low-grade index (1.4%+/-1.6%). We propose that foci of high- but not low-grade AAH may be potential precursor lesions of lung adenocarcinoma, especially with the BAC component.
authors.affiliation: Pathophysiological and Experimental Pathology, Department of Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Takaomi
authors.initials: T
authors.lastname: Koga
authors.forename: Shuichi
authors.initials: S
authors.lastname: Hashimoto
authors.forename: Kenji
authors.initials: K
authors.lastname: Sugio
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Yonemitsu
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Nakashima
authors.forename: Ichiro
authors.initials: I
authors.lastname: Yoshino
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Matsuo
authors.forename: Sepideh
authors.initials: S
authors.lastname: Mojtahedzadeh
authors.forename: Keizo
authors.initials: K
authors.lastname: Sugimachi
authors.forename: Katsuo
authors.initials: K
authors.lastname: Sueishi
mesh_terms: D002282:Adenocarcinoma, Bronchiolo-Alveolar / Q000473:pathology*; D018196:Carcinoma, Adenosquamous / Q000473:pathology; D018287:Carcinoma, Large Cell / Q000473:pathology; D018277:Carcinoma, Mucoepidermoid / Q000473:pathology; D018288:Carcinoma, Small Cell / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000473:pathology; D006801:Humans; D006965:Hyperplasia; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis; D008175:Lung Neoplasms / Q000473:pathology*
chemical_list: D019394:Ki-67 Antigen