I have recently gone through surgery to remove a tumor on my left shin. It is in the skin and diagnosed an undifferentiated polymorphic sarcoma. I am very confused about this because it is rare and little information seems to be available. I am suppose to make an appointment with my oncologist to see about setting up radiation therapy. I was told it should be done soon but also told that the wound needs to be completely healed first. I have no idea what the stage is for the tumor.