Presentation
Chronic pain of the right knee with abnormal knee x-rays (not shown).
Patient Data
Large multiseptated intramedullary tibial lesion of metaphyseal-diaphyseal location. It shows a fatty density (mean density = -120 HU) with central calcification or ossification and wall sclerosis. No cystic transformation, cortical breach or soft component is seen.
Case Discussion
CT features most consistent with an intraosseous lipoma of the tibia, stage 2 according to Milgram and co-workers.
Intraosseous lipomas are rare benign bone lesions seen in about 0.1-2.5% of all bone tumors. The calcaneum is the most common location (32%). Tibial location is seen in about 13% of cases.
If the lesion is not affecting bone stability, it is usually treated conservatively. In cases with pathological fractures are treated by curettage and bone grafting. Usually no recurrences after surgical therapy. Sporadic cases of malignant transformations have been described in the literature.
Additional contributor: ZE. Boudiaf, MD, CHU; Constantine, Algeria