Biology and outcome of childhood acute megakaryoblastic leukemia: a single institution's experience

Abstract

To describe the clinical and biologic features of pediatric acute megakaryoblastic leukemia (AMKL) and to identify prognostic factors, experience at St Jude Children's Research Hospital was reviewed. Of 281 patients with acute myeloid leukemia treated over a 14-year period, 41 (14.6%) had a diagnosis of AMKL. Six patients had Down syndrome and AMKL, 6 had secondary AMKL, and 29 had de novo AMKL. The median age of the 22 boys and 19 girls was 23.9 months (range, 6.7-208.9 months). The rate of remission induction was 60.5%, with a 48% rate of subsequent relapse. Patients with Down syndrome had a significantly higher 2-year event-free survival (EFS) estimate (83%) than did other patients with de novo AMKL (14%) or with secondary AMKL (20%; P < .038). Among patients who had de novo AMKL without Down syndrome, 2-year EFS was significantly higher after allogeneic bone marrow transplantation (26%) than after chemotherapy alone (0%; P ‫؍‬ .019) and significantly higher when performed during remission (46%) than when performed during persistent disease (0%; P ‫؍‬ .019). The 5-year survival estimates were significantly lower for de novo AMKL (10%) than for other forms of de novo AML (42%; P < .001). Treatment outcome is very poor for patients with AMKL in the absence of Down syndrome. Remission induction is the most important prognostic factor. Allogeneic transplantation during remission offers the best chance of cure; in the absence of remission, transplantation offers no advantage over chemotherapy alone. IntroductionAcute megakaryoblastic leukemia (AMKL) is a biologically heterogeneous form of acute myeloid leukemia (AML) and is recognized as the seventh subtype of AML (M7) within the FrenchAmerican-British (FAB) cooperative group classification system. 1 AMKL has a bimodal age distribution that peaks in early childhood (age Ͻ 3 years) and adulthood. [2][3][4][5][6] Between 1% and 10% of cases of AML in adults are identified as AMKL. 2,7 Although initially thought to be rare among children, AMKL has been diagnosed with increasing frequency in this age group, largely because of improvements in immunophenotyping. 5 Contemporary cooperative group studies have found that 3.1% to 10% of all cases of childhood AML are AMKL. [8][9][10][11] However, the exact incidence of AMKL in children remains undetermined.Acute megakaryoblastic leukemia is the most common form of AML in children with Down syndrome (DS), and its prognosis is excellent in this group of patients. 6,8,[12][13][14] AMKL in other children appears to be more heterogeneous, and its prognostic factors have not been well defined. 5,6 Since 1984, our institution has used systematic criteria to establish the diagnosis of AMKL. We reviewed the clinical and biologic characteristics and the outcomes of all 41 cases of childhood AMKL diagnosed at our institution since that time. Patients, materials, and methods PatientsAll cases of AMKL diagnosed between January 1985 and December 1998 at St Jude Children's Research Hospital were reviewed. Details of clinical presentation...

Acute megakaryoblastic leukemia: experience of GIMEMA trials

“…In spite of a good percentage of CR achievement, that could range, according to the different studies on pediatric and adults series, between 50% and 78%, the DFS is very short, with a median of 10 months. [8][9][10][11][12] In our study, these results were confirmed. We observed a CR rate of 50% with a median DFS of 9 months.…”

“…[8][9][10][11][12]23 This discrepancy could be due in part to the fact that in pediatric series patients with Down syndrome are observed and, among these, AMeL Leukemia occurs about 400-500 times more frequently than in other children. 24 In fact, among the 24 AMeL cases identified by Ribeiro et al, 10 there were five Down syndrome patients (20%), and in the series by Athale et al, 12 Down syndrome patients represented 14.6% of all AMeL cases. Another possible explanation could be that AMeL occurs more frequently in children than in adults.…”

“…Although a good percentage of patients achieve complete remission (CR), only a few patients survive beyond 5 years. [9][10][11][12] Clinical experience with this rare leukemia remains limited.…”

Treatment and long-term results in children with acute myeloid leukaemia treated according to the AIEOP AML protocols

“…The use of unrelated donors for ALLO_SCT in Italy is presently reserved to patients in second CR or to the few Treatment of childhood AML in Italypatients with M7 AML, as a recent study has documented a particularly dismal outcome for this latter subtype. 37 …”

Infiltração cutânea na leucemia megacariocítica aguda com expressão de CD56

“…1,2,3 Representa 3% a 5% dos casos de LMA e exibe uma curva de incidência de distribuição com um pico bimodal, ou seja, um pico em crianças menores de três anos e outro em idosos. 1,3,5,6,7 A utilização apenas de critérios morfológicos e citoquímicos não é suficiente para um diagnóstico correto, pois são células morfologicamente indistinguíveis, com reações citoquímicas Sudan Black (SB) e mieloperoxidase negativas. 1,2 Assim, a utilização de técnicas de imunofenotipagem é essencial para o diagnóstico diferencial, mostrando uma população de células leucêmicas com ausência da maioria dos marcadores linfóides e mielóides de superfície.…”