title: Comparison between CT tumor size and pathological tumor size in frozen section examinations of lung adenocarcinoma.
abstract: OBJECTIVE
  We examined the appropriate measurement for pathological tumor size by comparing radiological and pathological tumor size of resected lung adenocarcinoma in FSE.
  
  
  METHODS
  We reviewed records of 59 resected specimens of lung adenocarcinoma for FSE from January to December 2008. Specimens were well-inflated with saline by using an injector before cutting into segments. After selecting the tumor segment of maximal diameter, we compared three ways of measuring pathological tumor size by using paired t-test: (I) macroscopic tumor size (MTS), measured with a metal straight ruler, (II) microscopic frozen section tumor size (FSTS), and (III) microscopic paraffin section tumor size (PSTS). We compared each discrepancy rate (DR) [DR=(CT tumor size-pathological tumor size)/CT tumor size×100] (%) between tumors that were air-containing type and solid-density type on CT scans, and also compared the tumors with lepidic component rates (LCR) ≥50% and LCR <50%, by using Mann-Whitney U-tests.
  
  
  RESULTS
  FSE could diagnose malignancy with 100% accuracy. The mean CT tumor size was 18.36mm, and the mean pathological tumor sizes (MTS, FSTS, and PSTS) were 17.81, 14.29, and 14.23mm, respectively. FSTS and PSTS were significantly smaller than CT tumor size (p<0.001). The DR calculated with PSTS was significantly larger in air-containing than in solid-density tumors, and also larger in LCR ≥50% than in LCR <50% tumors.
  
  
  CONCLUSIONS
  FSE with the inflation method diagnosed malignancy with 100% accuracy. The lung specimen must be sufficiently inflated to prevent tissue shrinking, and we propose MTS as the definition for pathological tumor size in FSE. The greater discordance observed between CT tumor size and microscopic tumor size was assumed to be due to shrinkage of the lepidic component in the tumor.
authors.affiliation: Department of Pathology, Kanagawa Cancer Center, 2-3-2 Nakao, Asahi, Yokohama, Kanagawa 241-0815, Japan; Department of Thoracic Surgery, Kanagawa Cancer Center, 2-3-2 Nakao, Asahi, Yokohama, Kanagawa 241-0815, Japan; Department of Surgery, Yokohama City University, 3-9 Fukuura, Kanazawa, Yokohama, Kanagawa 236-0004, Japan. Electronic address: l401092k@yahoo.co.jp.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Isaka
authors.affiliation: Department of Pathology, Kanagawa Cancer Center, 2-3-2 Nakao, Asahi, Yokohama, Kanagawa 241-0815, Japan. Electronic address: yokose-t@kcch.jp.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Yokose
authors.affiliation: Department of Thoracic Surgery, Kanagawa Cancer Center, 2-3-2 Nakao, Asahi, Yokohama, Kanagawa 241-0815, Japan. Electronic address: h-ito@kcch.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ito
authors.affiliation: Department of Thoracic Surgery, Kanagawa Cancer Center, 2-3-2 Nakao, Asahi, Yokohama, Kanagawa 241-0815, Japan. Electronic address: nao.imamura@kcch.jp.
authors.forename: Naoko
authors.initials: N
authors.lastname: Imamura
authors.affiliation: Department of Thoracic Surgery, Kanagawa Cancer Center, 2-3-2 Nakao, Asahi, Yokohama, Kanagawa 241-0815, Japan. Electronic address: mit_lan_evo_2@hotmail.co.jp.
authors.forename: Masato
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Department of Thoracic Surgery, Kanagawa Cancer Center, 2-3-2 Nakao, Asahi, Yokohama, Kanagawa 241-0815, Japan. Electronic address: kentaro-imai@tea.ocn.ne.jp.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Imai
authors.affiliation: Department of Thoracic Surgery, Kanagawa Cancer Center, 2-3-2 Nakao, Asahi, Yokohama, Kanagawa 241-0815, Japan. Electronic address: nteppei@par.odn.ne.jp.
authors.forename: Teppei
authors.initials: T
authors.lastname: Nishii
authors.affiliation: Department of Surgery, Yokohama City University, 3-9 Fukuura, Kanazawa, Yokohama, Kanagawa 236-0004, Japan. Electronic address: tetsu.n.u@cotton.ocn.ne.jp.
authors.forename: Tetsukan
authors.initials: T
authors.lastname: Woo
authors.affiliation: Department of Thoracic Oncology, Kanagawa Cancer Center, 2-3-2 Nakao, Asahi, Yokohama, Kanagawa 241-0815, Japan. Electronic address: kozoyama@eb.mbn.or.jp.
authors.forename: Kouzo
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Department of Thoracic Surgery, Kanagawa Cancer Center, 2-3-2 Nakao, Asahi, Yokohama, Kanagawa 241-0815, Japan. Electronic address: nakayama-h@kcch.jp.
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Nakayama
authors.affiliation: Department of Surgery, Yokohama City University, 3-9 Fukuura, Kanazawa, Yokohama, Kanagawa 236-0004, Japan. Electronic address: mmasuda@yokohama-cu.ac.jp.
authors.forename: Munetaka
authors.initials: M
authors.lastname: Masuda
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003581:Cytodiagnosis; D005260:Female; D005629:Frozen Sections; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden
keywords: Adenocarcinoma; CT tumor size; Frozen section examinations; Inflation method; Lepidic; Lung cancer; Pathological tumor size