The Doctor At The Hospital Was Trying To Decide Whether

The doctor at the hospital was trying to decide whether or not to do a CT scan on my son, because he had mono and was still in severe pain long after the mono had cleared up. She said sometimes these black spots can appear and if they are not taken care of they could lead to cancer. She ultimately decided not to do the scan, and I forgot the name of the condition. Do you know the name of the condition she was referring to?