four causes of ulceration were identified : chemoradiation toxicity ( n = 2 ) , acute graft-versus-host disease ( gvhd ) ( n = 5 ) , opportunistic infections superimposed on either gvhd or toxicity from chemotherapy ( n = 4 ) , and epstein-barr virus-associated lymphoproliferative disorder ( n = 2 ) .
C0856825
acute
C0018133
gvhd