title: Primary colon cancer with a high serum PIVKA-II level.
abstract: BACKGROUND
  Protein induced by vitamin K absence/antagonist-II (PIVKA-II) is an abnormal protein, and several reports have demonstrated the efficacy of PIVKA-II in the diagnosis of hepatocellular carcinoma (HCC). We report an extremely rare case of adenocarcinoma of the colon with a high serum PIVKA-II level.
  
  
  METHODS
  A 95-year-old woman presented with right lower quadrant pain and appetite loss. An abdominal computed tomography scan and ultrasonography showed an ascending colon tumor and multiple metastatic tumors in the liver. The serum level of PIVKA-II was extremely high, 11,900ng/mL. Colonoscopic examination revealed a tumor accompanied by an ulcer in the ascending colon, which was highly suspicious for malignancy. Multiple biopsies showed well-differentiated adenocarcinoma of the colon, which was evaluated as colon cancer, stage IV. PIVKA-II-productive colon cancer was confirmed. Chemotherapy with TS-1 was administered. The patient died 3 months after initial admission.
  
  
  CONCLUSIONS
  The expression of PIVKA-II was detected in non-cancer areas, with non-specific expression observed in plasma cells in our case. There might be some possibility that hepatoid differentiation exists in other regions of the colon tumor or in the liver tumor, parenchymal cells or lung metastases, which were composed of PIVKA-II-positive and AFP-negative cells.
  
  
  CONCLUSIONS
  To the best of our knowledge, high serum levels of PIVKA-II resulting from colon adenocarcinoma have not been reported previously. We report this rare case together with a review of the literature.
authors.affiliation: Department of Surgery, Pippu Clinic, 2-10, 1 cyome Nakamachi, Pippu Town Kamikawa-gun, Hokkaido 078-0343, Japan. Electronic address: pippuclinickato@gold.ocn.ne.jp.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Kato
authors.affiliation: Department of Gastroenterology and Hepatology, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558,Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Iwasaki
authors.affiliation: Department of Surgery, Asahikawa Medical University, 1-1, 2-1 Midorigaoka, Asahikawa City 078-8510, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Taniguchi
authors.affiliation: Department of Surgery, Sapporo Hokuyu Hospital, 5-1, 6-6Higashi- Sappro, Shiroishi-ku Sapporo City 003-0006, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Onodera
authors.affiliation: Department of Surgery, Nihon University, 1-8-13 Surugadai Kanda, Chiyoda-ku, Tokyo 010-8309, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Matsuda
authors.affiliation: Department of Surgery, Pippu Clinic, 2-10, 1 cyome Nakamachi, Pippu Town Kamikawa-gun, Hokkaido 078-0343, Japan.
authors.forename: Takako
authors.initials: T
authors.lastname: Kawakami
authors.affiliation: Department of Surgery, Pippu Clinic, 2-10, 1 cyome Nakamachi, Pippu Town Kamikawa-gun, Hokkaido 078-0343, Japan.
authors.forename: Mineko
authors.initials: M
authors.lastname: Higuchi
authors.affiliation: Department of Surgery, Pippu Clinic, 2-10, 1 cyome Nakamachi, Pippu Town Kamikawa-gun, Hokkaido 078-0343, Japan.
authors.forename: Kimitaka
authors.initials: K
authors.lastname: Kato
authors.affiliation: Department of Surgery, Pippu Clinic, 2-10, 1 cyome Nakamachi, Pippu Town Kamikawa-gun, Hokkaido 078-0343, Japan.
authors.forename: Yurina
authors.initials: Y
authors.lastname: Kato
authors.affiliation: Department of Surgery, Asahikawa Medical University, 1-1, 2-1 Midorigaoka, Asahikawa City 078-8510, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Furukawa
keywords: Adenocarcinoma; Carbohydrate antigen 19–9 (CA 19–9); Carcinoembryonic antigen (CEA); Colon cancer; Protein induced by vitamin K absence/antagonist-II (PIVKA-II)