Imaging-Guided Percutaneous Biopsy of Pathologic Fractures: A Retrospective Analysis of 129 Cases

OBJECTIVE. The purpose of our study was to determine the diagnostic performance of imaging-guided percutaneous needle core biopsy and the factors associated with a non-diagnostic biopsy in patients with a pathologic fracture of the appendicular skeleton. MATERIALS AND METHODS. A retrospective audit was performed of 129 consecutive patients presenting with a pathologic fracture. All patients underwent percutaneous needle core biopsy using CT (n = 98), fluoroscopy (n = 15), or ultrasound (n = 16) guidance. In all cases, either MRI or CT was available before biopsy to assess the presence and degree of the extraosseous tumor mass. The resulting sample was classified as diagnostic (group 1) or nondiagnostic (group 2) on histopathologic study. Diagnostic performance was evaluated on the basis of the diagnostic yield and the diagnostic accuracy, and these were related to the site of the lesion and presence or absence of an extraosseous mass. RESULTS. Ninety-nine masses (77%) were classified as group 1 and 30 (23%) as group 2. The average cross-sectional diameter of lesions in group 1 was 5.7 x 5.9 cm. Of the 30 lesions composing group 2, no soft-tissue component was identified on prebiopsy cross-sectional imaging in 27 lesions (90%), but the remaining three (10%) showed a smaller extraosseous soft-tissue component compared with the lesions in group 1. CONCLUSION. Imaging-guided core biopsy is a reliable method for obtaining a tissue diagnosis in pathologic fracture of the appendicular skeleton with a high rate of accuracy. However, those lesions that are purely intraosseous or have only very small extraosseous components are more likely to be associated with a nondiagnostic biopsy and should be considered for a primary open procedure.