Primary pulmonary osteosarcoma: a report of 4 cases and a review of the literature.

Primary pulmonary osteosarcoma is very rare. Most cases are secondary deposits from primaries arising in the appendicular skeleton. Four cases of primary osteogenic sarcoma of the lung are described and the literature reviewed for previously reported cases. These pulmonary tumors occur in patients who are in their fourth to seventh decades, that is, an older age group than their primary bone equivalent. There is a slight male predominance. There appears to be a propensity for the left lung, especially the left upper lobe. The clinical presentation is similar to primary (epithelial) lung cancer. Differentiation from pleomorphic carcinomas and other sarcomas is discussed. We know of no predisposing factor(s) in our cases for the development of this tumor.