RESUMEN
1,200 cases of bone tumors were reviewed from the Orthopedic Hospital "Magdalena de las Salinas" between 1982 and 1989. 66.7% of them were benign tumors, 14.3% pseudotumoral lesions, 10.1% metastatic tumors, 8.6% primary malignant tumors, and 0.3% were malignant invasive tumors to bone. The most frequently found benign tumors were: osteochondroma, enchondroma and giant cell tumor; the most frequent pseudotumoral lesions were metaphyseal fibrous defects, solitary bone cysts and fibrous dysplasia; the most frequent primary malignant tumor was osteosarcoma. Prevalence, frequency, distribution, sex, most frequent ages, affected bones, multicentricity, and aggregated fractures, as well as the site of the primary lesion in metastatic and invading tumors, were similar to those reported in the classical series.