Morphobiochemical analysis of calcified chondroblastic osteosarcoma of the mandible.

Although the morphological features of osteosarcoma have been widely investigated, there is little information about its biochemistry. In this study, materials obtained from human calcified chondroblastic osteosarcoma were analyzed by microanalytical techniques revealing both morphological and biochemical characteristics at the same tissue site. Morphologically, tumor cells in the surface area showed atypical and mitotic figures. Hypertrophic chondroblastic cells appeared and increased in density closer to the calcified region. Almost all cells in the calcified region were hypertrophic. Biochemical analysis revealed that alkaline phosphatase activity was steeply elevated and inorganic phosphate gradually increased towards the calcified region. The spread of the calcified region was coincident with the contents of acid-soluble phosphate and calcium of the tumor. These results were similar to those found in endochondral calcification of epiphyseal growth cartilage.