title: An unusual leiomyosarcoma of the uterus containing osteoclast-like giant cells.
abstract: An unusual variant of a poorly differentiated leiomyosarcoma of the uterus, containing osteoclast-like giant cells, is described. Areas of the resected tumor bore a close resemblance to giant cell tumor of bone. It is postulated that these giant cells, as well as the osteoclast-like giant cells reported in a number of tumors of other tissues, originate from the monocyte/histiocyte group of cells. The diagnosis of leiomyosarcoma was possible only after the tumor had been examined in the electron microscope. The ultrastructural features are consistent with a smooth muscle origin of the neoplasm; the final assessment is based on the relative proportions and frequency of such structures as: bundles of myofilaments with focal densities, marginal densities, pinocytotic vesicles, and an external lamina.
mesh_terms: D002467:Cell Nucleus / Q000648:ultrastructure; D003094:Collagen; D003593:Cytoplasm / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D005110:Extracellular Space; D005260:Female; D006056:Golgi Apparatus / Q000648:ultrastructure; D006801:Humans; D007044:Hysterectomy; D007890:Leiomyosarcoma / Q000175:diagnosis / Q000473:pathology*; D008854:Microscopy, Electron; D008875:Middle Aged; D008928:Mitochondria / Q000648:ultrastructure; D008940:Mitotic Index; D010010:Osteoclasts / Q000648:ultrastructure; D011554:Pseudopodia / Q000648:ultrastructure; D013194:Staining and Labeling; D014594:Uterine Neoplasms / Q000175:diagnosis / Q000473:pathology*; D014599:Uterus / Q000473:pathology*
chemical_list: D003094:Collagen