title: C-KIT-positive undifferentiated tumor of the liver: A case report.
abstract: With recent advances in cancer stem cell analysis, it has been postulated that the transformation of hepatic stem and progenitor cells underlies the development of certain liver cancers. Human C-KIT is a transmembrane type III receptor protein with intrinsic tyrosine kinase activity that has been proposed as a marker for human embryonic stem cells. In addition, human C-KIT functions in maintaining the undifferentiated state of stem cells, and has been identified as a marker for human hematopoietic and hepatic stem/progenitor cells. The present study identified an unusual case of a C-KIT-positive hepatic tumor with an undifferentiated stem cell phenotype distinct from existing descriptions of liver tumors. A 69-year-old male with Ampulla of Vater (AoV) cancer was admitted to the hospital for the treatment of a hepatic mass that was incidentally detected during evaluation of AoV cancer. Microscopically, the hepatic tumor was composed of solidly packed small, round and uniform undifferentiated cells, which resembled that of a small-blue-round-cell tumor. The immunophenotype of neoplastic cells (C-KIT+/EpCAM+/E-cadherin+/keratin 7-/keratin 19-/α-fetoprotein-/albumin-) supported primitive stem cell features with no hepatic or biliary phenotypes. Polymerase chain reaction and direct DNA sequencing revealed no C-KIT mutations. It is suggested that this tumor may have originated from transformed C-KIT+/EpCAM+/E-cadherin+cells, which are more primitive and undifferentiated than bipotential hepatic progenitor cells.
authors.affiliation: Department of Pathology, Chonbuk National University, Medical School, Research Institute for Endocrine Sciences and Research Institute of Clinical Medicine, Jeonju 561-756, Republic of Korea.
authors.forename: Hyun Hee
authors.initials: HH
authors.lastname: Chu
authors.affiliation: Department of Surgery, Chonbuk National University, Medical School, Research Institute for Endocrine Sciences and Research Institute of Clinical Medicine, Jeonju 561-756, Republic of Korea.
authors.forename: Baik Hwan
authors.initials: BH
authors.lastname: Cho
authors.affiliation: Department of Radiology, Chonbuk National University, Medical School, Research Institute for Endocrine Sciences and Research Institute of Clinical Medicine, Jeonju 561-756, Republic of Korea.
authors.forename: Ji Soo
authors.initials: JS
authors.lastname: Song
authors.affiliation: Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, Republic of Korea.
authors.forename: Kyung Mi
authors.initials: KM
authors.lastname: Kim
authors.affiliation: Department of Pathology, Chonbuk National University, Medical School, Research Institute for Endocrine Sciences and Research Institute of Clinical Medicine, Jeonju 561-756, Republic of Korea.
authors.forename: Woo Sung
authors.initials: WS
authors.lastname: Moon
keywords: C-KIT; liver; stem cell