[Successful treatment of myelodysplastic syndromes complicated by myeloid sarcoma with haploidentical allogeneic hematopoietic stem cell transplantation using post-transplant cyclophosphamide].

Using post-transplant cyclophosphamide (PTCy-haplo), haploidentical allogeneic hematopoietic stem cell transplantation has shown a surge in popularity in recent years. There are, however, only a few reports of PTCy-haplo being used to treat myelodysplastic syndromes (MDS) that have been complicated by myeloid sarcoma (MS). An immuno-suppressive therapy was given to a 25-year-old man who was diagnosed with low-risk MDS in September 2007. After an ileocecal ulcer biopsy that revealed MS in July 2019, a chromosomal analysis of the bone marrow cells in August 2019 revealed loss of chromosome 7, which is associated with poor prognosis. Because the patient lacked an HLA-matched sibling donor, he underwent PTCy-haplo in December 2019. On day 33, complete remission and donor chimerism was achieved. Ileocecal ulcer scarring was discovered by a colonoscopy on day 54. Grade I cutaneous acute graft-versus-host disease was discovered approximately on day 30 and treated with topical steroids. PTCy-haplo may be an effective treatment for MS.