The thumb metacarpal is abnormal. There is a tumor centered on the metacarpal which has extended from the bone and into the surrounding soft tissues as an extraosseous soft tissue mass. There is associated edema in the bone and extending into the muscles surrounding the tumor.
This tumor is centered on the bone and in pediatric patients, the short differential for bone tumors runs to:
The age of the patient, location, and soft tissue mass point towards Ewing sarcoma.
Ewing sarcoma was confirmed histologically.