Analysis of nondiagnostic results after image-guided needle biopsies of musculoskeletal lesions

Background/rationale: Image-guided needle biopsies are commonly used to diagnose musculoskeletal tumors, but nondiagnostic (ND) results can delay diagnosis and treatment. It is important to understand which factors or diagnoses predispose to a ND result so that appropriate patient education or a possible change in the clinical plan can be made. Currently it is unclear which factors or specific lesions are more likely to lead to a ND result after image-guided needle biopsy. Questions/purposes: We therefore identified specific factors and diagnoses most likely to yield ND results. We also asked whether an image-guided needle biopsy of bone and soft tissue lesions is an accurate and clinically useful tool. Methods: We retrospectively reviewed data from a prospectively collected database for a case-control study of 508 image-guided needle biopsies of patients with suspected musculoskeletal tumors between 2003 and 2008. Results: The interpretations of 453 of the 508 (89%) needle biopsies were accurate and clinically useful. Forty-five biopsies (9%) were ND and 10 (2%) were incorrect (IC). Bone lesions had a higher ND rate than soft tissue lesions (13% vs. 4%). The specific diagnosis with the highest ND rate was histiocytosis. Elbow and forearm locations had higher ND rates than average. Malignant tumors had a higher IC rate than benign tumors (5% vs. 0%); fibromyxoid sarcoma and rare subtypes of osteosarcoma had higher IC rates than other diagnoses. Repeat needle or open biopsies were performed in 71 (14%) patients. Bone lesions were more likely than soft tissue lesions to require repeat biopsies (18% vs. 9%). Conclusions: A high rate of accuracy and clinical usefulness is possible with image-guided needle biopsies of musculoskeletal lesions. We believe these biopsies appropriate in selected circumstances but a key factor for appropriate use is an experienced musculoskeletal tumor team with frequent communication to correlate clinical, radiographic, and histologic information for each patient.