A 78-year-old woman referred by the Department of Obstetrics and Gynecology was recommended for orthopedic surgery because a cystic lesion in the left femoral proximal area was found by bone mineral densitometry (BMD). Computed tomography (CT) scan and general X-ray performed in the orthopedic department found a benign tumor. An intramedullary nail was inserted. Curettage and bone graft were performed. A radiologic technologist is important for the morphological observation of the femur in femoral BMD.