Unusual form and location for a tumor: multiosseous Ewing sarcoma in the foot.

Ewing sarcoma, as the prototype of a small round blue cell tumor of bone, typically affects adolescents and young adults. The most commonly involved sites include the diaphyses of long bones, ribs, and flat bones, such as the pelvis and scapula. We report a case of multifocal Ewing sarcoma involving multiple bones in the foot. Given the multifocal nature of the disease confined to the foot, the initial impression was that of osteomyelitis. We describe the histologic, radiologic, and diagnostic features of the tumor and outline treatment and prognosis. To our knowledge, this is the first report of multifocal Ewing sarcoma involving multiple bones in the foot.