Myeloid sarcoma of the appendix in a 2-year-old patient with acute myeloid leukemia

Abstract

Myeloid sarcoma (MS), a rare extramedullary manifestation of acute myeloid leukemia (AML), may present concurrently with, precede, or occur during bone marrow lesion relapse. We report the case of a patient with acute abdomen associated with primary appendiceal pathology that developed during remission induction therapy. The patient was a 2-year-old boy who relapsed eight months after completing chemotherapy for AML (M5 subtype). The patient underwent surgical resection and was diagnosed with appendiceal MS. Bone marrow examination after chemotherapy indicated remission, and the patient underwent bone marrow transplantation. An extramedullary lesion was detected in the patient’s intestinal tract 5 months after transplantation. Appendiceal MS is rare even in adults. Herein, we report the youngest pediatric patient with appendiceal MS in Japan to date.