title: Case report 679. Central low-grade osteosarcoma with foci of dedifferentiation.
abstract: An infrequently encountered case of well-differentiated CLOS containing dedifferentiated tumor foci in a 28-year-old Japanese man is reported. The patient died from widespread metastases with a microscopic appearance identical to the anaplastic dedifferentiated lesions of the original tumor. This is, to our knowledge, the first report of a case of CLOS with dedifferentiation at the time of initial surgery. The literature concerning CLOS was reviewed and the diagnostic features of CLOS discussed.
authors.affiliation: Department of Pathology, Jikei University, School of Medicine, Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Iemoto
authors.forename: S
authors.initials: S
authors.lastname: Ushigome
authors.forename: M
authors.initials: M
authors.lastname: Fukunaga
authors.forename: T
authors.initials: T
authors.lastname: Nikaido
authors.forename: K
authors.initials: K
authors.lastname: Asanuma
mesh_terms: D000328:Adult; D001859:Bone Neoplasms / Q000556:secondary; D005266:Femoral Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008297:Male; D012516:Osteosarcoma / Q000000981:diagnostic imaging / Q000473:pathology*; D011859:Radiography; D012878:Skin Neoplasms / Q000556:secondary