School ager with bumps on the bilateral calves

Radiograph of multiple osteochondromas of the knee
AP radiograph of the knees shows bilateral lesions arising from the medial aspect of each tibial metaphysis, with a bony stalk growing away from the metaphysis with a lytic lesion growing at the tip of each stalk with a narrow zone of transition and no associated periosteal reaction.

The diagnosis was bilateral tibial osteochondromas.