title: Carcinosarcoma of the gallbladder. A case report with immunohistochemical and ultrastructural studies.
abstract: The authors present the histologic features, immunohistochemical findings, and ultrastructure of a carcinosarcoma of the gallbladder containing rhabdomyosarcoma as a mesenchymal element. A pedunculated polypoid tumor protruded into the lumen from the fundus of the gallbladder. The neoplasm contained two divergent components. One was malignant mesenchymal tissue with rhabdomyoblastic differentiation; the other was ordinary adenocarcinoma which was observed predominantly at the base of the polyp. Immunohistochemically, the cytoplasm of the rhabdomyoblasts stained with anti-myoglobin, myosin, and muscle actin antibodies. Ultrastructurally, there were a large number of malignant mesenchymal tissues in which various stages of differentiated rhabdomyoblasts were noted. Ultrastructural study was particularly valuable for the identification of sarcomatous elements.
authors.affiliation: First Department of Pathology, Yamaguchi University School of Medicine, Ube, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ishihara
authors.forename: H
authors.initials: H
authors.lastname: Kawano
authors.forename: M
authors.initials: M
authors.lastname: Takahashi
authors.forename: T
authors.initials: T
authors.lastname: Yokota
authors.forename: F
authors.initials: F
authors.lastname: Uchino
authors.forename: N
authors.initials: N
authors.lastname: Matsumoto
authors.forename: N
authors.initials: N
authors.lastname: Fukuyama
mesh_terms: D002296:Carcinosarcoma / Q000473:pathology / Q000648:ultrastructure*; D005260:Female; D005706:Gallbladder Neoplasms / Q000473:pathology / Q000648:ultrastructure*; D006801:Humans; D008854:Microscopy, Electron; D008875:Middle Aged; D012208:Rhabdomyosarcoma / Q000473:pathology