title: Natural History of Pulmonary Subsolid Nodules: A Prospective Multicenter Study.
abstract: The purpose of this study was to evaluate the natural course of the progression of pulmonary subsolid nodules (SSNs).
  
  
  
  Eight facilities participated in this study. A total of 795 patients with 1229 SSNs were assessed for the frequency of invasive adenocarcinomas. SSNs were classified into three categories: pure ground-glass nodules (PGGNs), heterogeneous GGNs (HGGNs) (solid component detected only in lung windows), and part-solid nodules.
  
  
  
  The mean prospective follow-up period was 4.3 ± 2.5 years. SSNs were classified at baseline as follows: 1046 PGGNs, 81 HGGNs, and 102 part-solid nodules. Among the 1046 PGGNs, 13 (1.2%) developed into HGGNs and 56 (5.4%) developed into part-solid nodules. Among the 81 HGGNs, 16 (19.8%) developed into part-solid nodules. Thus, the SSNs at the final follow-up were classified as follows: 977 PGGNs, 78 HGGNs, and 174 part-solid nodules. Of the 977 PGGNs, 35 were resected (nine minimally invasive adenocarcinomas [MIAs], 21 adenocarcinomas in situ [AIS], and five atypical adenomatous hyperplasias). Of the 78 HGGNs, seven were resected (five MIAs and two AIS). Of the 174 part-solid nodules, 49 were resected (12 invasive adenocarcinomas, 26 MIAs, 10 AIS, and one adenomatous hyperplasia). For the PGGNs, the mean period until their development into part-solid nodules was 3.8 ± 2.0 years, whereas the mean period for the HGGNs was 2.1 ± 2.3 years (p = 0.0004).
  
  
  
  This study revealed the frequencies and periods of development from PGGNs and HGGNs into part-solid nodules. Invasive adenocarcinomas were diagnosed only among the part-solid nodules, corresponding to 1% of all 1229 SSNs.
authors.affiliation: Cancer Screening Division, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan; Cancer Screening Center, National Cancer Center Hospital, Tokyo, Japan; Department of Pulmonology, Tokyo General Hospital, Tokyo, Japan. Electronic address: rkaki@ncc.go.jp.
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Kakinuma
authors.affiliation: Department of Pathology, University of Tsukuba, Faculty of Medicine, Tsukuba, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Noguchi
authors.affiliation: Department of Clinical Oncology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Kazuto
authors.initials: K
authors.lastname: Ashizawa
authors.affiliation: Department of Radiology, Osaka National Hospital, Osaka, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Kuriyama
authors.affiliation: Department of Pathology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Akiko Miyagi
authors.initials: AM
authors.lastname: Maeshima
authors.affiliation: Department of Radiology, Niigata Cancer Center, Niigata, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Koizumi
authors.affiliation: Department of Thoracic Oncology, Kanagawa Cancer Center, Yokohama, Japan.
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Kondo
authors.affiliation: Department of Thoracic Surgery, Tochigi Cancer Center, Utsunomiya, Japan.
authors.forename: Haruhisa
authors.initials: H
authors.lastname: Matsuguma
authors.affiliation: Department of Radiology, Shiga University of Medical Science, Otsu, Japan.
authors.forename: Norihisa
authors.initials: N
authors.lastname: Nitta
authors.affiliation: Department of Thoracic Oncology, National Cancer Center Hospital East, Kashiwa, Japan.
authors.forename: Hironobu
authors.initials: H
authors.lastname: Ohmatsu
authors.affiliation: Department of General Thoracic Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
authors.forename: Jiro
authors.initials: J
authors.lastname: Okami
authors.affiliation: Department of Thoracic Surgery, Shikoku Cancer Center, Matsuyama, Japan; Department of Thoracic Surgery, Iwakuni Clinical Center, Iwakuni, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suehisa
authors.affiliation: Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan; Division of Epidemiology, Center for Public Health Sciences, National Cancer Center, Tokyo, Japan.
authors.forename: Taiki
authors.initials: T
authors.lastname: Yamaji
authors.affiliation: Department of General Thoracic Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan; Department of Thoracic Surgery, Yao Municipal Hospital, Yao, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Kodama
authors.affiliation: Department of Thoracic Oncology, Tochigi Cancer Center, Utsunomiya, Japan; Department of Pulmonology, Tsuboi Cancer Center Hospital, Koriyama, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Mori
authors.affiliation: Department of Thoracic Oncology, Kanagawa Cancer Center, Yokohama, Japan.
authors.forename: Kouzo
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Department of Surgical Pathology, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Matsuno
authors.affiliation: Department of Radiology, University of the Ryukyus, Faculty of Medicine, Okinawa, Japan.
authors.forename: Sadayuki
authors.initials: S
authors.lastname: Murayama
authors.affiliation: Department of Radiology, Shiga University of Medical Science, Otsu, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Murata
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D014057:Tomography, X-Ray Computed
keywords: Computed tomography; Ground-glass nodule; Lung adenocarcinoma; Natural history; Subsolid nodule