My son was diagnosed with Metastatic Ewing Sarcoma of the Bone in August 2013 that was later changed to Metastatic DSRCT and then after further studies it was determined to be an Undifferentiated Small Cell Malignancy of the Pelvis with multiple metastases up the Spine. He recently completed his initial treatment protocol. Treatment included 14 alternating cycles of VDC and IE every two weeks and 30 proton treatments. He just had his followup scans including a MRI of his pelvis, a MRI of his L-spine and a Chest CT. The MRIs were explained to us but not the CT so my question stems from there. In the CT findings it states, No pericardial or pleural effusion. Few scattered subcentimeter in short axis nodes and nodes containing fatty hila in the chest without significant enlargement by size criteria. What does that mean and is it something we should be concerned about?