Extramedullary recurrences with or without bone marrow involvement are reported in up to a half of leukemic relapses after BMT. Our report describes a case of an extramedullary recurrence and breast relapse after second-allografting in a female patient with Ph+-acute lymphoblastic leukemia (ALL), occurring when there was active hepatic GHVD. This case illustrates the complex relationship between graft-versus-host disease (GVHD) and graft-versus-leukemia since she had no evidence of leukemia in her marrow demonstrating 100% full-donor chimerism while she had ALL relapse in her breast.