Giant Osteolipoma Fixed to the Greater Trochanter of the Femur in a Seventy-Year-Old Elderly Woman.

A lipoma containing mature osseous elements is called osteolipoma. This article describes a giant osteolipoma fixed to the periosteum of the greater trochanter of the femur. A seventy-year-old woman presented with a large subcutaneous mass in the right buttock which had been present for six years. On local examination, a giant mass that was ovoid, firm, non-tender, well demarcated, subcutaneous, and relatively fixed to the greater trochanter was palpated in the right buttock. A medical imaging and fluoro-deoxy-glucose (FDG) bone scan revealed a large lipomatous and metabolically active lesion arising from the periosteum of the greater trochanter of femur. The excisional mass of 17 × 8 × 7 cm was well encapsulated and had an osseous basal portion. Cut sections of the mass revealed mainly yellow fatty tissue surrounded by a thin fibrous capsule with numerous interlacing thin lamellar bony structures. The definitive pathological diagnosis was osteolipoma without evidence of malignancy. No recurrence was observed at eight months follow-up. Osteolipoma with an osseous basal portion is rare. Surgical excision is the treatment of choice and the prognosis is good. To the best of our knowledge, this is the first report of an unusual giant osteolipoma fixed to the periosteum of the greater trochanter of the femur.