Intraosseous lipoma
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Intraosseous lipoma is the most frequent lipogenic lesion of bone. Patients range in age from 5 to 85 years, with the lesions being most frequently discovered in the 4th and 5th decades of life. Males are slightly more commonly affected than females. Although intraosseous lesions may be discovered incidentally, pain has been reported in up to 66% of cases. Pain may be mechanical due to expansile remodeling of bone or it may be related to the ischemic changes that frequently accompany these lesions. Frequent locations include Intertrochanteric region (34% of cases), Calcaneus (8%), Ilium (8%), tibia (13%), fibula (10%), humerus (5%), and ribs (5%). Long bone lesions typically occur in the metaphysis. Typically are solitary lesions. Treatment of intraosseous lipomas is often not indicated with asymptomatic lesions or those discovered incidentally. Symptomatic lipomas may be treated with curettage and bone graft placement.
Diagnosis
The imaging findings are
- The radiologic appearance of intraosseous lipoma depends on the histologic composition of the lesion (contain varying amounts of fat, bone, fibrous tissue, and cystic degeneration)
- Intraosseous lipomas composed solely of fat are radiolucent, well-circumscribed lesions that frequently are associated with mild focal expansile remodeling of the affected bone. This is nonspecific appearance and shares the same features of unicameral bone cyst, fibrous dysplasia, and plasmacytoma.
- Intraosseous lipoma containing only fat is easily differentiated from other primary osseous lesions at MR imaging or CT because both modalities offer the ability to document the intrinsic lesional adipose tissue.
- CT demonstrates the low attenuation of fat (<–60 to –100 HU)
- MRI shows T1 prolongation and T2 shortening similar to subcutaneous fat.
Patient #1: Calcaneal lipoma
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Sag PD -
Sag STIR -
Coronal PD
