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

Key Clinical Message 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. 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.