title: Dumbbell-shaped leiomyosarcoma of the inferior vena cava with foci of rhabdoid changes and osteoclast-type giant cells.
abstract: An inferior vena cava (IVC) tumor was incidentally found in a 67-year-old Japanese man. The resected tumor was lobulated and multinodular, measuring 14.0 x 6.5 x 7.0 cm, showing a dumbbell-shaped appearance with a central constriction. The tumor showed both intra- and extra-luminal growth. The tumor was primarily composed of well-differentiated leiomyosarcoma. Spindle tumor cells in the well-differentiated area were positive for vimentin, muscle actin, alpha-smooth muscle actin, and desmin. Foci of rhabdoid cells and osteoclast-type multinucleated giant cells were also found. Rhabdoid cells ultrastructurally had paranuclear aggregates or whorls of intermediate filaments that were positive for vimentin, low molecular weight cytokeratin, and desmin. Osteoclast-type multinucleated giant cells were positive for only CD68 antigen, suggesting a reactive histiocytic lineage. To the best of our knowledge, this is the first case of IVC leiomyosarcoma accompanied by both rhabdoid tumor cells and osteoclast-type reactive multinucleated giant cells. These unusual features should be kept in mind in the diagnosis of dumbbell-shaped retroperitoneal tumors that involve the IVC.
authors.affiliation: Department of Pathology, Chiba University Hospital, Chiba, Japan. nikaido@mb.kcom.ne.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Nikaido
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Endo
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nimura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ishikura
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Ushigome
mesh_terms: D000368:Aged; D017809:Fatal Outcome; D015726:Giant Cells / Q000473:pathology / Q000648:ultrastructure; D006801:Humans; D007150:Immunohistochemistry; D007890:Leiomyosarcoma / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D019043:Vascular Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D014682:Vena Cava, Inferior / Q000473:pathology* / Q000601:surgery