Clinical Characteristics And Prognostic Analysis Of Myeloid Sarcoma: A Report Of 21 Cases

ObjectiveTo analyze the clinico-pathological characteristics, immunohistochemistry, treatment approaches of myeloid sarcoma (MS), and assess the prognosis.MethodsTwenty-one MS patients were enrolled in this study, and were divided into two groups by the bone marrow findings and history of disease. Group I included 13 isolated MS patients who preceded AML, Group II included 8 leukemic MS patients with the abnormalities in bone marrow or a history of leukemia. Clinical characteristics, pathological findings, treatment response and prognosis were analyzed.ResultsThe median age at diagnosis was 34 years (range,18-68 years). The ratio of male to female was 1:1.1. The most common locations for MS included skin, lymph node and breast, whereas they may occur in uterine and vaginal wall with a high incidence of 24.1%. Myeloperoxidase (20/21,95.2%) was to identify the most sensitive and specific immunohistochemical markers. Three cases (3/21,14.3%) showed chromosomal abnormalities, of which two cases occurred in chromosome 8. Group I (13 cases with isolated MS) all patients received systemic anti-AML chemotherapy. The median survival time was 20 months (range,4-63 months), of which four cases (4/13,30.8%) progressed to AML within 16 months (range,6-62 months). GroupⅡ(8 cases with leukemic MS), five patients received systemic chemotherapy. Treatment response showed that the complete remission rate was 80% (4/5) and the relapse rate was 75% (3/4). Using Kaplan-Meier survival analysis, we found the survival outcome of patients with isolated MS is superior to leukemic MS patients. Two year survival rates were 46.2% and 12.5%, respectively. There was no difference between two groups in age and gender distribution. The categorical variables, included gender, age, single or multiple, chromosomal abnormalities, with or without surgery had no influence on the survival outcome, P values were 0.296,0.860,0.077,0.093 and 0.290, respectively.ConclusionThe survival outcome of patients with isolated MS is superior to leukemic MS patients. Early diagnosis and aggressive treatment play a key role on improving the prognosis of MS. Anti-AML chemotherapy is still the first line treatment. The treatment choice of refractory and relapsed MS is still difficult. The standardized and unified strategies is needed to develop for effective treatment, by expanding the case samples and designing prospective studies.