OBJECTIVE: In the pediatric group, the radiological diagnosis of bone tumors of the hip is difficult and presents some peculiarities, but reviewed literature does not approach this specific problem. The objective of the present study was to investigate the existence of reliable radiological patterns for the differential diagnosis of these tumors. MATERIALS AND METHODS: Radiological findings of bone tumors of the hip in ten patients in the age range between 8 and 19 years have been reviewed. RESULTS: Bone reaction (sclerosis or lysis), periosteal reaction (lamellar with single or multiple layers, or radial), tumor extent in the bone and level of soft tissues invasion have presented low specificity. Soft tissue calcifications, when considered as a whole, were non-specific. However, when those calcifications with varied shapes and sizes, nearby the affected bone (pattern I) were separated from those, thin and amorphous, away from the bone (pattern II), we have observed that the pattern I was totally non-specific, and the pattern II was found in the three cases of osteosarcoma (100%) and in only one case of Ewing's sarcoma (16.6%). CONCLUSION: In the present study, pattern II calcifications have shown a 100% sensitivity and 90% specificity for osteosarcoma. However, their importance may be not limited to the radiological diagnosis. Pattern II calcifications indicate probably ideal sites for biopsy.

Keywords: Bone tumors, Ilium, Hip, Pelvis, Pediatrics, Computed tomography