Presentation
Trauma.
Patient Data
A well-defined lucent lesion with sclerotic margin is noted in the anterior part of the calcaneus.
No obvious fracture line could be noted.
A well-defined oval-shaped mass is seen in the anterior part of the calcaneus that shows predominantly fat signal with central areas of fluid signal intensity in all pulse sequences.
Anterior talofibular ligament is torn.
Sprain in deep deltoid fibres is found, accompanied by subcortical bone marrow oedema in the medial aspect of the talar body, considerable effusion in the ankle joint and surrounding soft tissue oedema.
Os naviculare bone is detected.
Case Discussion
Features on X-ray and MR images are compatible with calcaneal lipoma with central degenerative changes.
Although intraosseous lipomas can be found anywhere within the skeleton, the lower limb accounts for the majority of cases and the calcaneus is the most common site. On the other hand, lipoma is considered the most frequent calcaneal bone lesion.
On X-ray, other differential diagnoses for a lucent anterior calcaneal lesion may include:
pseudotumour of the calcaneus: normal triangular lucency