[Extramedullary relapse of acute myeloid leukemia with pericardial effusion after allogeneic hematopoietic stem cell transplantation].

A 62-year-old man presented with anemia and neutropenia, and was diagnosed with acute myeloid leukemia with myelodysplasia-related changes (AML-MRC). His disease was refractory to treatment, but went into remission after a third regimen, venetoclax plus azacitidine (Ven+Aza). However, the disease relapsed during treatment for an infection, and he underwent allogeneic peripheral blood stem cell transplant while not in remission. He did not achieve remission after transplantation, but treatment with azacitidine and early discontinuation of immunosuppressants led to remission. However, relapse occurred on day250 in the form of pericardial effusion. After drainage, Ven+Aza therapy was started again, and the pericardial effusion disappeared rapidly. The patient has been continuing the same treatment, and has remained in remission for more than 15 months. Isolated extramedullary relapse caused by pericardial effusion is rare, and this case illustrates that Ven+Aza therapy may be effective.