title: [Ultrastructural study of osteosarcoma].
abstract: Twenty one cases of common type of osteosarcoma were investigated light and electron microscopically. Ultrastructurally, osteosarcoma could be classified into 4 types of cells, osteoblast-like, chondroblast-like, fibroblast-like and small round cell types. Another type of tumor cells, occasionally encountered in the tumor tissue, were myofibroblastic, osteoclastic and filopodial cells of subdivided groups. All of these were constituents of groups of tumor tissue, and were histopathologically manifested with osteoblastic, chondroblastic, fibroblastic and small round cell types of each predominant cell groups, respectively. However, the main tumor cells essentially consisted of osteoblast-like cell with prominent osteoid formation; hydroxyapatite with dense crystalline structure was characteristically deposited in the dense collagenous matrix. Osteoids also showed several structural varieties of matrix vesicles. These structural relationship to the osteoid were also discussed.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D012516:Osteosarcoma / Q000648:ultrastructure*