Post-transplant relapse of therapy-related MDS as gastric myeloid sarcoma: Case report and review of literature

INTRODUCTION: Myelodysplastic syndrome (MDS) are hematologic neoplasms characterized by morphologic dysplasia and ineffective hematopoiesis in the bone marrow. The only potentially curative therapy is stem cell transplant. However, relapse remains a major challenge and is seen in about 25–40% of cases. Myeloid sarcoma presenting as relapse post allogeneic transplant for myeloid neoplasms is rare. We report the sentinel case of a patient with MDS who relapsed as gastric myeloid sarcoma 1 ½ years after allogeneic stem cell transplant. CASE PRESENTATION: Sixty-nine-year-old male who was diagnosed with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) in 2006 and transitional cell bladder carcinoma in 2008. In 2011, he developed therapy-related myeloid neoplasm t(7;22) and no excess blasts. He was treated with Vidaza followed by a MUD hematopoietic stem cell transplant on 8/24/2012. In 2013 the patient developed anorexia and gastric biopsies showed severe gastritis. Repeat gastric biopsy on 02/05/2014 showed an extensive mononuclear infiltrate which could easily be confused with lymphocytes but staining showed myeloid sarcoma. Marrow was negative. The patient remained refractory to therapy and expired 08/10/2016. CONCLUSION: In summary, we report the first case of GI relapse of MDS as a myeloid sarcoma post-transplant. We seek to alert our audience of this potentially serious diagnostic pitfall, particularly one that can be relatively easily resolved on the basis of immunohistochemical profiling.