Effective treatment of peritoneal myeloid sarcoma with decitabine and venetoclax: A case report.

Myeloid sarcomas (MS) are rare extramedullary manifestations of myeloid progenitor cells occurring with or without acute myeloid leukemia. Peritoneal MS is exceptionally uncommon, with no established treatment guidelines, but treatment has historically consisted of cytotoxic chemotherapy. We present the case of a 78-year-old female with 60% CD34+, HLA-DR+, and CD33+ myeloblasts in ascitic fluid, while bone marrow biopsy demonstrated only molecular evidence of the leukemic clone with FLT3-ITD, ASXL1, and TET2 mutations. Findings were consistent with primary peritoneal myeloid sarcoma. Due to chemotherapy ineligibility, the patient was treated with decitabine and venetoclax. After nine cycles, she demonstrated a complete radiographic response. To our knowledge, this is the first case report of a patient with primary peritoneal MS treated with a combination of a hypomethylating agent and venetoclax.