title: Anaplastic thyroid carcinoma with osteosarcomatous differentiation.
abstract: A case of a thyroid tumour with the cytological and histological pattern of anaplastic carcinoma with extensive osteosarcomatous differentiation in a 54-year-old Kaukasian woman is presented. Immunohistochemical examination revealed keratin-vimentin co-expression in anaplastic tumour areas. According to the WHO classification of thyroid tumours the present tumour has to be classified as an anaplastic carcinoma. A retrospective survey revealed only twenty-four comparable cases in the literature. The present tumour most likely represents an example of a neoplastic epithelial-mesenchymal metaplasia. The possible mechanisms of the occurrence of thyroid tumours with mixed epithelial-mesenchymal differentiation are briefly discussed.
authors.affiliation: Department of Pathology, Westfälische Wilhelms-University of Münster, FRG.
authors.forename: S
authors.initials: S
authors.lastname: Blasius
authors.forename: G
authors.initials: G
authors.lastname: Edel
authors.forename: J
authors.initials: J
authors.lastname: Grünert
authors.forename: W
authors.initials: W
authors.lastname: Böcker
authors.forename: K W
authors.initials: KW
authors.lastname: Schmid
mesh_terms: D002277:Carcinoma / Q000145:classification / Q000175:diagnosis / Q000473:pathology*; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D012516:Osteosarcoma / Q000145:classification / Q000175:diagnosis / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000145:classification / Q000175:diagnosis / Q000473:pathology*