title: Multinucleation followed by an acytokinetic cell division in myxofibrosarcoma with giant cell proliferation.
abstract: BACKGROUND
  Multinucleated cells are frequently seen in association with a malignant neoplasm. Some of these multinucleated cells are considered to be neoplastic. The mechanism of neoplastic multinucleation remains unknown, but is considered to be induced by either cell-cell fusion or acytokinetic cell division. Myxofibrosarcoma consists of spindled and pleomorphic tumor cells and bizarre multinucleated giant cells. Some of these multinucleated cells are considered to be neoplastic.
  
  
  METHODS
  We studied the mitotic activity of the multinucleated cells by Ki-67 immunohistochemistry, and the dynamics and differentiation by live-cell video microscopy in the two myxofibrosarcoma cell lines to determine whether the mechanism of multinucleation is cell-cell fusion or acytokinetic cell division
  
  
  RESULTS
  A Ki-67 immunohistochemical analysis revealed a high positive rate of multinucleated cells, as well as mononuclear cells, and mitotic ability was shown in the multinucleated cells. In live-cell video microscopy, most of the multinucleated cells were induced via the process of acytokinetic cell division.
  
  
  CONCLUSIONS
  The current study indicates that a vulnerability of the cytoskeleton components, such as the contractile ring, causes multinucleation to occur from the telophase to the cytokinesis of the cell cycle.
authors.affiliation: Division of Orthopedic Surgery, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan. arii2075@med.niigata-u.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Ariizumi
authors.forename: Akira
authors.initials: A
authors.lastname: Ogose
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kawashima
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Hotta
authors.forename: Hajime
authors.initials: H
authors.lastname: Umezu
authors.forename: Naoto
authors.initials: N
authors.lastname: Endo