Clinical Analysis Of 15 Cases Of T(16;21)(p11;q22) Acute Myeloid Leukemia

Objectives:to investigate clinical characteristics of acute myeloid leukemia(AML)with t(16;21)(pll;q22),and the curative effect and prognosis.Methods:15 AML patients with t(16;21)(pll;q22)were retrospectively reviewed involved in cell morphology,immunophenotype,cytogenetics,molecular biology as well as clinical features and prognosis.Results:11 patients of 15 were males,4 were females,median age was 45(23-64)years old.According to the FAB classification,11 patients were classified as M5b,1 as M5a,3 as M4.Vacuolation of leukemic cells was found in 4 patients.Increase of micromegakaryocytes was found in 9 patients,especially the micromegakaryocytes with one nucleus.14 cases had CD56 antigen expression,1 case had no this antigen expression.All the patients had the clonal chromosomal abnormality,t(1 6;21)(p11;q22),11 cases had additional karyotype abnormalities,6 cases were identified as complexed karyotype abnormalities,2 patients had der(1;16)(q10;p10),1 had monosomal karyotype.Complete remission(CR)rate was 93%,CR rate after first course inducton chemotherapy was 50%,5 patients received allogeneic hematopoietic stem cell transplantation(allo-HSCT),1 patient received autologous hematopoietic stem cell transplantaton(auto-HSCT).2 cases had central nervous system leukemia after first course induction chemotherapy,their bone marrow had achieved CR.Median relapse time was 7.5(4.6-13.6)months,2-year overall survival(OS)rate was 34.6%,the prognosis was similar to the unfavorable group.2 of 5 patients who received allo-HSCT had survival period for more than 54 months.Conclusion:t(16;21)(pll;q22)is a rare chromosomal abnormality,AML patients with this translocation have distinct morphology,such as vacuolation,increase of micromegakaryocytes,and have CD56 expression.AML with t(16;21)(pll;q22)ofen has additional karyotype abnormalities,extramedullary involvement,and has a poor prognosis,allo-HSCT could improve the prognosis.