Diagnostic accuracy and clinical utility of fine-needle aspiration cytology in the diagnosis of clinically primary bone lesions. 
Optimal treatment of primary bone sarcomas requires minimal disturbance of the tumor prior to preoperative radiation and chemotherapy.  Currently, carefully planned incisional or cutting needle biopsies are the favored methods for procurement of specimens.  Recently, fine-needle aspiration has gained favor as the initial diagnostic procedure at some centers.  We investigated the diagnostic accuracy and the effects of errors in diagnosis and of complications on the patient's course in a series of 101 patients presenting with lesions clinically believed to have arisen in bone.  We found that 29% of aspirates were insufficient for the diagnosis; 41% of aspirates yielded a correct diagnosis that had a significant favorable impact on the patient's course, while 20% of aspirates gave a correct diagnosis that did not significantly influence therapy.  In 7% of cases, the aspirates were associated with an incorrect diagnosis that negatively influenced therapy, and in an additional 3% of cases an incorrect diagnosis was obtained that had no impact on patient outcome.  No complications were encountered in this series of patients.