Abstract: To analyze the clinical characteristics,  imaging characteristics,  pathological characteristics of the misdiagnosed case and the limitations of MRI in the diagnosis of myeloid sarcoma (MS)  to gain deeper understanding of  MS. MS is a special type of acute myeloid leukemia, which is rarely seen in children. Due to its diverse onset and manifestations,  MS is easy to be misdiagnosed clinically. Histopathological diagnosis is the gold standard. Biopsy combined with imaging examination is the key to the diagnosis of MS. Early biopsy of the tumor can effectively reduce misdiagnosis and determine prognosis.

Key words: sarcoma, , myeloid；child；immunophenotyping；diagnosis