Lipoma of the bone.

A fitly-one year old man reported to the outpatients department, Liaquat National Hospital, with a painful nodule on the distal end of the femur. The slowly growing nodule had grown to roughly 2 ems, in the last decade. The plain film radiographs showed a well-defined lytic lesion diagnosed as osteoid osteoma. The radiograph of the femur also showed a radiolucent mass with lobulated margins and strands of ossification in the distal third of the anteromedial aspect of the femur diagnosed as a periosteal lipoma. The surgical specimen of the first lesion was removed intact and sent to the pathology laboratory for histopathological diagnosis. it was a soft, yellow, well-circumscribed mass, measuring 2.5 ems, in length and 2.0 ems in diameter. The mass was enclosed in a thin rim of bone. Histopathological examination revealed mature adipose tissue containing atrophic bone trabeculae. The lesion was devoid of hematopoietic elements, dystroph ic calcification, haemorrhage or necrosis.