Intracortical lipoma of the femur.

Intracortical lipoma is an extremely rare benign primary bone tumor. We encountered a case of an intracortical lipoma found incidentally in the femur of a 31-year-old female. Magnetic resonance imaging and computed tomography of the femur demonstrated an intracortical fatty lesion in the posterolateral aspect of the diaphysis. The intracortical lesion showed some intramedullary extension, multiple septations, and dot-like calcifications. Intralesional curettage was performed. Histologically, the tumor consisted of mature, viable adipocytes without foci of fat necrosis or dystrophic calcification.