Hi, my grandson has lymph nodes both side of neck areas. His pedrician done lab test and he said it is mono. My grandson is only 4 1/2 years old. After a month the lymph nodes lessen the swelling but still careful for him not to play any sports due to might have enlarged spleen. The doctor also waiting for another test which is about any contaminating the cats. Please give us more advice about this condition. Thank you.