Bone Tumors with an Associated Pathologic Fracture: Differentiation between Benign and Malignant Status Using Radiologic Findings

Abstract

Purpose: To determine whether benign and malignant bone tumors with associated pathologic fractures can be differentiated using radiologic findings. Materials and Methods: Seventy-eight patients (47 men and 31 women, age range: 1–93 years) with a bone tumor and an associated pathologic fracture from 2004 to 2013 constituted the retrospective study cohort. The tumor size, margin, and enhancement patterns; the presence of sclerotic margin, the peritumoral bone marrow, soft tissue edema, extra-osseous soft tissue mass, intratumoral cystic/hemorrhagic/ necrotic regions, mineralization/sclerotic regions, periosteal reaction and its appearance; and cortical change and its appearance were evaluated on all images. Differences between the imaging characteristics of malignant and benign pathologic fractures were compared using Pearson’s chi-square test and the 2-sample ttest. Results: There were 22 benign and 56 malignant bone tumors. Some factors were found to significantly differentiate between benign and malignant tumors; specifically, ill-defined tumor margin, the presence of sclerotic tumor margin and an extraosseous soft tissue mass, the absence of cystic/necrotic/hemorrhagic portions in a mass, the homogeneous enhancement pattern, and the presence of a displaced fracture and of underlying cortical change were suggestive of malignant pathologic fractures. Conclusion: Some imaging findings were helpful for differentiating between benign and malignant pathologic fractures.