Diagnosis of primary bone tumors with image-guided percutaneous biopsy: experience with 110 tumors.

PURPOSE To determine the diagnostic accuracy of image-guided percutaneous biopsy in 110 primary bone tumors of varying internal compositions. MATERIALS AND METHODS One hundred ten consecutive patients with primary bone tumors underwent biopsy with computed tomography (CT) or fluoroscopy. Ninety-one patients underwent surgical follow-up and 19 received medical treatment and underwent subsequent imaging studies. Final analysis of bone biopsy results included tumor type, malignancy, final tumor grade, biopsy complications, and effect on eventual treatment outcome. RESULTS Seventy-seven tumors were malignant and 33 were benign. Most common tumors at biopsy were osteosarcoma (n = 20), lymphoma (n = 18), chondrosarcoma (n = 16), and giant cell tumor (n = 16). Correct final diagnosis was attained in 97 (88%) patients. Sixty-three lesions were solid nonsclerotic; 26, sclerotic; and 21, lytic with cystic centers containing internal areas of fluid, hemorrhage, or necrosis. In six of 21 lesions with a predominant cystic internal composition, problems occurred in determining a final diagnosis. In 13 patients, definite correct diagnosis was not obtained with initial percutaneous bone biopsy. Of these patients, benign bone tumors were better defined with surgical specimens in seven, a diagnosis of malignancy was changed to that of another malignancy in four, and the diagnosis was changed from benign to malignant in two. Nine patients underwent open surgical biopsy. Seven of the difficult cases were of cystic tumors with hemorrhagic fluid levels visible at CT or magnetic resonance imaging. The only complication was a small hematoma. CONCLUSION Percutaneous biopsy of primary bone tumors is safe and accurate for diagnosis and grade of specific tumor. In cases with nondiagnostic biopsy, open-procedure biopsy is likely to be associated with similar diagnostic difficulties.