Smoldering type adult T‐cell leukemia/lymphoma effectively treated with mogamulizumab (anti‐CC chemokine receptor 4 monoclonal antibody)—A case report

: The use of mogamulizumab needs careful consideration because of severe adverse reactions such as graft-vs-host disease. However, refractory specific skin lesions of smoldering type adult T-cell leukemia/lymphoma can be effectively treated with mogamulizumab when patients have no opportunity to receive hematopoietic stem cell transplantation like our case.