Epidemiology
A rare deep lipoma located against the surface of the bone, usually in adults. Its direct relationship to the cortex explains why it sometimes looks like a bone lesion, even though the main component is fatty.
Basic features
It can be associated with cortical thickening or reactive bony prominence and can produce a firm mass or discomfort from friction.
Usual treatment
Resection is reserved for symptoms, growth, compression, or an uncertain diagnosis on imaging.
Outcomes and prognosis
Local control is usually definitive when it is fully resected along with the symptomatic reactive component.