[Desquamative esophagitis associated with unrelated allogeneic peripheral blood stem cell transplantation using the FBM conditioning regimen].

Desquamative esophagitis (DE) is a rare benign condition characterized by sheet-like shedding of esophageal squamous epithelial tissue. Although cases of drug-induced DE, such as those induced by direct oral anticoagulants, have been reported, cases of DE complicated with hematopoietic stem cell transplantation (HSCT) are rare. We herein report the case of a 52-year-old woman with FLT3-ITD mutation-positive acute myeloid leukemia who presented with DE immediately after HSCT. Allogeneic peripheral blood HSCT with FBM (fludarabine 180 mg/m2, busulfan 12.8 mg/m2, and melphalan 80 mg/m2) was performed during the first remission. Tacrolimus plus short-term methotrexate was planned for graft-versus-host disease prevention. Common Terminology Criteria for Adverse Events grade 3 equivalent vomiting was observed during treatment with the conditioning regimen. On day 5 after HSCT, a white band of 10 cm in length and 1 cm in width was discharged from the oral cavity during vomiting. Upper gastrointestinal endoscopy revealed mucosal detachment in the entire esophagus and the diagnosis of DE was made. DE improved on providing conservative treatment. We concluded that the mechanical pressure that developed on the esophagus due to frequent vomiting contributed to the mucosal detachment owing to regimen-related toxicity. Even in the FBM regimen, which is widely used as a conditioning regimen, caution is required to prevent DE.