Eleven cases of intraosseous lipoma of the calcaneus.

Intraosseous lipomas are rare benign primary bone tumors, with an incidence of one per thousand bone tumors. We studied eleven cases of intraosseous lipoma of the calcaneus. All the patients received radiographic examinations and MRI with T1-and T2-weighted images with Gd-DTPA enhancement. Seven patients received tumor curettage. Plain radiographs demonstrated that all of the lesions showed clear osteolysis surrounded by a sclerotic margin in the central body of the calcaneus. MRI revealed that all the lesions had demarcated homogenous high signal intensity lesions on both T1- and T2-weighted images, which strongly suggested adipose tissue. In 5 cases, the center of the lesion showed low signal intensity lesions on T1-weighted images, suggesting the existence of central necrosis or cyst formation. After excising the tumors of 7 patients, there was no local tumor recurrence. Surgical intervention was considered unnecessary in all cases after the diagnosis of an intraosseous lipoma was determined by MRI.