title: Indeterminate pulmonary nodules in colorectal cancer.
abstract: OBJECTIVE
  To investigate the clinicopathologic parameters of pulmonary metastasis in colorectal cancer (CRC) patients after lung operation of indeterminate pulmonary nodules (IPNs).
  
  
  METHODS
  From a prospective database of CRC patients, 40 cases that underwent lung operation between November 2008 and December 2012 for suspicious metastatic pulmonary nodules on chest computed tomography (CT) were enrolled. The decision to perform a lung operation was made if the patient met the following criteria: (1) completely resected or resectable primary CRC; (2) completely resectable IPNs; (3) controlled or controllable extrapulmonary metastasis; and (4) adequate general condition and pulmonary function to tolerate pulmonary operation. Lung operation was performed by a thoracic surgeon without CT-guided biopsy for pathologic confirmation.
  
  
  RESULTS
  A total of 40 cases of lung resection was performed in 29 patients. Five patients underwent repeated lung resection. The final pathology result showed metastasis from the CRC in 30 cases (75%) and benign pathology in 10 cases (25%). The primary tumor site was the rectum in 26/30 (86.6%) cases with pulmonary metastasis, but only 3/10 (30%) cases in the benign group had a primary rectal cancer (P = 0.001). Positron emission tomography (PET)-CT was performed for 22/30 (73.4%) patients in the lung metastasis group and for 6/10 (60.0%) patients in the benign group. PET-CT revealed hot uptake of (18)fluorine 2-fluoro-2-deoxy-D-glucose with all IPNs in both groups. The group with pulmonary metastasis had a higher incidence of primary rectal cancer (P = 0.001), a more advanced tumor stage (P = 0.011), and more frequent lymphatic invasion of tumor cells (P = 0.005). Six cases with previous liver metastasectomy were present in the lung metastasis group. Serum carcinoembryonic antigen levels before lung operation were not elevated in any of the patients.
  
  
  CONCLUSIONS
  The stage and location of the primary tumor and tumor cell infiltration of lymphatics provide useful indicators for deciding on lung resection of IPNs in CRC.
authors.affiliation: Eun-Joo Jung, Su-Ran Kim, Chun-Geun Ryu, Jin Hee Paik, Dae-Yong Hwang, Department of Surgery, Colorectal Cancer Center, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul 143-729, South Korea.
authors.forename: Eun-Joo
authors.initials: EJ
authors.lastname: Jung
authors.affiliation: Eun-Joo Jung, Su-Ran Kim, Chun-Geun Ryu, Jin Hee Paik, Dae-Yong Hwang, Department of Surgery, Colorectal Cancer Center, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul 143-729, South Korea.
authors.forename: Su-Ran
authors.initials: SR
authors.lastname: Kim
authors.affiliation: Eun-Joo Jung, Su-Ran Kim, Chun-Geun Ryu, Jin Hee Paik, Dae-Yong Hwang, Department of Surgery, Colorectal Cancer Center, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul 143-729, South Korea.
authors.forename: Chun-Geun
authors.initials: CG
authors.lastname: Ryu
authors.affiliation: Eun-Joo Jung, Su-Ran Kim, Chun-Geun Ryu, Jin Hee Paik, Dae-Yong Hwang, Department of Surgery, Colorectal Cancer Center, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul 143-729, South Korea.
authors.forename: Jin Hee
authors.initials: JH
authors.lastname: Paik
authors.affiliation: Eun-Joo Jung, Su-Ran Kim, Chun-Geun Ryu, Jin Hee Paik, Dae-Yong Hwang, Department of Surgery, Colorectal Cancer Center, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul 143-729, South Korea.
authors.forename: Jeong Geun
authors.initials: JG
authors.lastname: Yi
authors.affiliation: Eun-Joo Jung, Su-Ran Kim, Chun-Geun Ryu, Jin Hee Paik, Dae-Yong Hwang, Department of Surgery, Colorectal Cancer Center, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul 143-729, South Korea.
authors.forename: Dae-Yong
authors.initials: DY
authors.lastname: Hwang
mesh_terms: D000368:Aged; D015179:Colorectal Neoplasms / Q000473:pathology*; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000556:secondary* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D055613:Multiple Pulmonary Nodules / Q000556:secondary* / Q000601:surgery; D009367:Neoplasm Staging; D018579:Patient Selection; D011013:Pneumonectomy; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D003074:Solitary Pulmonary Nodule / Q000556:secondary* / Q000601:surgery; D014057:Tomography, X-Ray Computed
keywords: Chest computed tomography; Colorectal neoplasm; Indeterminate pulmonary nodule; Lung metastasis; Lung neoplasm