Clinical features of acute megakaryocytic leukemia in children: analysis of 14 cases / 白血病·淋巴瘤

ABSTRACT

Objective:To investigate the clinical features of acute megakaryocytic leukemia (AMKL) in children.Methods:The clinical data of 14 children with AMKL in Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology from January 2012 to July 2021 were retrospectively analyzed, and the related literature was reviewed.Results:Among 14 children with AMKL, there were 5 males and 9 females, and the median age of onset was 19 months (0.1-109 months); 1 case was Down syndrome-related AMKL, and 13 cases were non-Down syndrome-related AMKL. Most of the children presented with fever, anemia or bleeding symptoms, and a few patients presented with joint pain as the primary symptom. Some children were accompanied by extramedullary infiltration such as hepatomegaly, splenomegaly or lymphadenovarix. Initial investigations of 14 children showed that the median white blood count, hemoglobin concentration and platelet count were 10.67×10 9/L [(6.56-83.62)×10 9/L], 84 g/L (55-121 g/L), 37×10 9/L [(8-1443) ×10 9/L], respectively, and the median proportion of naive cells in peripheral blood was 0.09 (0.00-0.79). Bone marrow smear showed that the primitive megakaryocytes were characterized by various size and irregular form, a few of which had cytoplasmic vacuoles, and the median proportion of bone marrow primitive megakaryocytes was 0.636 (0.332-0.976); the nuclei were round or irregular, with multiple nucleoli or hidden nucleoli. RAS staining was partially positive, and immunohistochemical assay showed that POX, AS-DNCE and α-NBE were negative. Detection of megakaryocyte-associated antigens by flow cytometry showed 12 children expressed CD41a or CD61, and 10 children expressed CD42b. Among 3 children who completed chemotherapy, 1 case of Down syndrome-related AMKL and 1 case of non-Down syndrome-related AMKL were event-free survival, and 1 case of non-Down syndrome-related AMKL died after bone marrow relapse. Conclusions:The clinical manifestations and biological characteristics of children with AMKL are complicated and the prognosis is poor. Some children can achieve disease-free survival through chemotherapy alone.