My Five Year Old Granddaughter Had An MRI Which Showed

My five year old granddaughter had an MRI which showed nasopharangeal effacement and mild thickening of her tonsils. She was treated approximately two months ago for mononucleosis based on neck swelling and positive Epstein Barr test. However, she didn't exhibit the usual signs of mono(i.e. severe lethargy or splenic swelling). She also recovered rather quickly. What could be going on?