Radiologic Findings of Intraosseous Lipoma of Long Bones

Abstract

Purpose To investigate radiologic findings of intraosseous lipoma on plain radiograph and magnetic resonance imaging (MRI). Materials and Methods Twenty-seven radiologically or pathologically confirmed intraosseous lipomas of long bones were included in the study. The size, involved bone and site, bone destruction pattern, border, internal calcification, bony expansion, cortical disruption and endosteal erosion were retrospectively analyzed on plain radiograph. The cases were classified into three stages based on calcification and cystic change. Eccentricity, margin, signal intensity of internal fatty portion, and presence of enhancement were analyzed. Results Twelve tumors were located in femur and 8 in humerus. Proximal metaphysis was the most common involved site, with 14 cases. All tumors had geographic bone destruction, with sclerotic rim in 18 cases on plain radiograph. Internal calcification was seen in 18 cases and bony expansion in 6 cases. Twenty-three cases had cystic change in MRI. Eleven cases had eccentric location. The margins were well-defined in 11 cases. High signal intensity of fatty portion on fat-sat T2-weighted image was present in 17 cases. Contrast enhancement was seen in 17 cases. Conclusion Knowledge of plain radiographic and MRI findings of intraosseous lipoma of long bones is valuable to the tumor diagnosis differentiation from other bone lesions.

Keywords

• mri
• radiography
• bone neoplasms
• lipoma