Primary cardiac osteosarcoma: multidisciplinary aspects applicable to extraskeletal osteosarcoma generally.

An osteosarcoma, primary in the right ventricular epicardium, produced pericardial constriction. Intense activity on technetium-99m bone scintigraphy led to a correct preoperative diagnosis. Biopsy of unrepresentative tissue clouded the diagnosis, and autopsy resolved the issue. Several clinicopathologic correlations are presented. Major therapeutic advances mandate early recognition of extraskeletal osteosarcoma, and the topic is reviewed in regard to cardiac cancers in general. The need to biopsy both hard and fleshy areas of unusual tumors is reviewed.