Rare case of intraosseous lipoma with proximal femoral localization causing cortical expansion.

Intraosseous lipoma has a 1% incidence among the primary tumors of the bone, and it frequently occurs in the calcaneous. As it is rare, it may be mistaken for nonossifying fibroma, aneurismal bone cyst, simple bone cyst, bone infarct and chondroid tumors. Intraosseous lipomas are usually followed up conservatively due to their spontaneous involution. However, surgery is required in the presence of fracture risk, malignant transformation potential and/or extensive pain. Herein we report a case with intraosseous lipoma involving the intertrochanteric femur and the collum femoris, causing cortical expansion. This presentation is extremely unusual for this type of tumor both in terms of localization and radiology. As the patient was symptomatic with extensive pain, we treated the patient by curettage and bone grafting.