Microspectrophotometric Quantitation of DNA in Bone Tumors with Giant Cells (Osteoclastoma, Osteosarcoma and Chondroblastoma)

Abstract

A microspectrophotometric study of DNA content was carried out on cells from three types of bone tumor--osteoclastoma, chondroblastoma, and osteosarcoma--in all of which the formation of multinucleated giant cells occurs. Giant cells of osteoclastic type were present in all the tumors, with contents of DNA which were constant, uniform and diploid in character for each nucleus individually considered. Since there were no nuclei with reduced or increased content of DNA, mitotic proliferation or gemmation can be excluded. Instead, the evidence suggests the formation of giant cells through a mechanism of cellular fusion. In contrast, the stromal cells of the osteoclastomas and the chondroblastomas gave evidence of DNA synthesis, thus proving their proliferative capacity in both tumors. The osteosarcomas showed a very irregular distribution of DNA, and generally the nuclear content of DNA exceeded the diploid DNA content.