Lymphoma or Mononucleosis?

Hi,
I have a situation with my brother, He is 32, He is in hospital now but nobody knows exactly what is wrong with him!
He told me that he had Herpes simplex on his upper lip and when he went to the doctor, he recommended some kind of corticosteroid ointment and when he didn't respond to them they prescribed Dexamethasone injection (8 of them in 4 days). After 3-4 days his throat begins to swells and it got bigger and bigger since and he started to experience fever and chill afterward.
We decided to take him to a hospital at first they gave him some antibiotics but nothing has change, every doctor comes up with a new diagnosis,one day they say it might be Mononucleosis, then they say it might be Lymphoma or leukemia.
yesterday they did a biopsy on his neck and they result won't go out until Saturday :( I really don't know what to do? this waiting is killing me ....
He still has his fever and chills, he lost weight but he feels better now. he is just so tired and confused!
Would you please help me with that, what is it really?
many thanks in advance .

[Mochadelicious]

I'm sorry to hear about your brother.  I honestly don't know what his diagnosis is.  The only definitive way to know is with a biopsy and it sounds like you'll get the results of that soon.  The tiredness, fever and weight loss could be lymphoma/leukemia, but it could be a lot of other things too.  

Has he had blood work done?  How's his LDH level?  Elevated LDH can also point to lymphoma/leukemia.  I hope the biopsy results come back with good news tomorrow.