title: Clinicopathological characteristics and prognosis of non-lepidic invasive adenocarcinoma presenting as ground glass opacity nodule.
abstract: BACKGROUND
  Ground glass opacity (GGO) generally associated with the lepidic component of lung adenocarcinoma. However, in some cases, GGO nodules have been associated with invasive adenocarcinomas, where a lepidic component is minimal or absent. The purpose of this study is to evaluate the clinicopathological characteristics and prognosis of non-lepidic invasive adenocarcinoma presenting as GGO nodules.
  
  
  METHODS
  We reviewed computed tomography (CT) images from 168 patients diagnosed with non-lepidic invasive adenocarcinoma classified as stage T1N0M0 (≤3 cm) who underwent curative anatomical resection. Tumors were classified according to radiologic features: 31 were GGO predominant (Group A) and 137 were solid predominant (Group B). The clinicopathological findings and recurrence free survival were used as outcome measures.
  
  
  RESULTS
  The mean percentages of micropapillary and solid component in tumor was higher in Group B than Group A (P<0.001) Pleural invasion and lymphatic invasion were more frequently seen in Group B. The presence of tumors with a micropapillary component was higher in Group B (P=0.040). The 3-year recurrence-free survival was lower in Group B than Group A (80.4%vs. 100%, P=0.019). Risk factors for recurrence such as presence of a micropapillary component and lymphatic invasion were more frequently seen in Group B.
  
  
  CONCLUSIONS
  Non-lepidic invasive adenocarcinoma presenting as GGO has fewer risk factors and better prognosis when compared with those presenting as solid tumors. Therefore, the presence of GGO on chest CT is a good prognostic indicator for lung cancer irrespective of histomorphologic classification.
authors.affiliation: Department of Thoracic & Cardiovascular Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Youngkyu
authors.initials: Y
authors.lastname: Moon
authors.affiliation: Department of Thoracic & Cardiovascular Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Sook Whan
authors.initials: SW
authors.lastname: Sung
authors.affiliation: Department of Hospital Pathology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Kyo Young
authors.initials: KY
authors.lastname: Lee
authors.affiliation: Department of Thoracic & Cardiovascular Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Jae Kil
authors.initials: JK
authors.lastname: Park
keywords: Lung cancer; ground glass opacity (GGO); invasive adenocarcinoma; prognosis