Primary bone tumors: percutaneous needle biopsy. Radiologic-pathologic study of 222 biopsies.

Findings of 222 needle biopsies were evaluated to determine the accuracy of the procedure in diagnosis, the role of the biopsy in limb-salvage procedures, the contribution of needle biopsy in the assessment of tumor effect in patients receiving chemotherapy or radiotherapy, and reasons for failure to obtain diagnostic tissue. The overall accuracy of needle biopsy in diagnosis of benign and malignant tumors was 78.6%. The major tumor categories included osteosarcoma (50 patients), giant-cell tumor (33 patients), Ewing sarcoma (22 patients), and spindle-cell sarcoma (15 patients). The accuracy of needle biopsy in diagnosis for these tumors was 78%, 88%, 95%, and 87%, respectively. The results of follow-up needle biopsy were encouraging, with roughly a 70% adequacy in the patients who had osteosarcoma and 50% in the patients who had Ewing sarcoma. The major reason for failure to obtain tissue for diagnosis in 17 of 35 patients was the presence of blastic tumors. The presence of cystic lesions and faulty technique were other reasons for failure. Percutaneous needle biopsy in patients who have primary bone tumors is a helpful diagnostic tool, forms an important part of the limb-salvage procedure, and contributes to the assessment of tumor effects in patients receiving chemotherapy or radiotherapy. To minimize failure in obtaining adequate tissue for diagnosis, biopsy specimens of blastic tumors should be obtained from their soft tissue components, lytic areas, or the least dense areas, while a smear of aspirate from cystic lesions should be prepared for cytologic examination and the clot embedded in paraffin for histologic study.