Fifteen patients with positive conventional radiographs for morpho-structural neoplastic involvement of bone, were systematically submitted to US with a high-frequency probe (7.5 MHz). US evaluation was aimed at testing, relative to conventional radiography, the sensitivity of the former technique in recognizing the main elementary signs of bone involvement--e.g., cortical interruption, periosteal reaction, and extraosseous spread. In 13 cases where conventional radiography had shown cortical bone involvement, US always confirmed the radiographic findings, showing cortical interruption in all cases and allowing a preliminary evaluation of lesion size in 10 cases. Morphological and structural alterations of bone profile--i.e., interruption or evident thinning of the hyperechoic line corresponding to the cortical profile--were the main and preliminary signs of pathologic skeletal involvement. US is suggested as a complementary and integrative technique to conventional radiology, because it allows elementary signs of morpho-structural alterations of the cortical bone to be identified, and a preliminary evaluation of tumor size to be made.