Figure 13b. Hypertrophic peroneal tubercle in a 22-year-old man who presented with a hard, tender mass on the lateral aspect of the foot. (a) SSD image of the skin shows a protuberance just distal to the lateral malleolus (arrow). (b) Lateral VR image of the bones and tendons shows that a hypertrophic peroneal tubercle of the calcaneus is responsible for the protuberance. The peroneal tendons are splayed around the tubercle (arrow). (c) Lateral SSD image shows enlargement of the peroneal tubercle (arrow). Blue area indicates the fibula.