Primary bone neoplasia following single inhalation exposure to 90SrCl2 in beagle dogs

Beagle dogs were observed for their life-span following single inhalation exposure to graded levels of 90SrCl2. Because of the soluble chemical form of the aerosol, 90Sr was rapidly translocated from lung and deposited in bone where it was retained for a long period of time. Forty-five primary bone tumors occurred in 31 of 66 exposed dogs. Of these, 27 were classified as different subtypes of osteosarcoma. Twenty-one tumors metastasized, with the lung being the most frequent site of metastasis (76%). Four carcinomas arising from soft tissues adjacent to bones of the skull were also considered to be 90Sr-induced. In contrast to bone tumors arising in Beagle dogs chronically exposed to 90Sr through ingestion, lesions of radiation osteodystrophy were minimal in this study, indicating that these lesions were not a necessary precursor of osteosarcoma development. The high incidence of hemangiosarcomas (31%) and telangiectatic osteosarcomas (11%) in addition to osteosarcomas suggests that these neoplasms may have a common cell or origin, a multipotent mesenchymal cell with the potential for various morphologic expressions dependent upon local environmental factors