Acute megakaryoblastic leukemia in down's syndrome: Report of a case and review of cytogenetic findings

Abstract

A case of a child with trisomy 21 and acute megakaryoblastic leukemia (AMBL) is reported. Histological examination of the bone marrow showed progressive fibrosis and replacement with megakaryoblasts. The diagnosis was confirmed by platelet peroxidase reaction and immunofluorescent staining with anti-factor VIII. Serial cytogenetic studies using banding techniques at various stages during the course of the disease (preleukemia, leukemia, remission, and relapse) showed several chromosomal abnormalities (unbalanced translocation between chromosomes 1 and 4 leading to trisomy 1q, trisomy 7q, monosomy 7p, and a reciprocal translocation between chromosomes 10 and 16). AMBL in childhood is probably more common than previously reported. Any association between AMBL and a particular cytogenetic abnormality must await further cytogenetic studies, specifically those employing banding techniques.

Down syndrome, transient myeloproliferative disorder, and infantile liver fibrosis

“…Relating TMD to congenital leukemia in the form of acute megakaryoblastic leukemia FAB M7 (AMKL) that is also frequently manifested by Down syndrome neonates [21,22] is not admissible initially. Nevertheless, the course of the leukemoid reaction shows some characteristic symptoms specific for TMD: (a) the leukocytes count decreases post partum within a few weeks or months without any antileukemic therapy while the patient recovers satisfactorily [1,23]; (b) the number of blasts in bone marrow is low compared with the count in peripheral blood [24]; (c) in contrast to the picture of congenital leukemia, the blasts show the karyotype of trisomy 21 without other clonal chromosomal abnormalities [25][26][27]; (d) extramedullary hematopoiesis of all three maturing cell lineages can be demonstrated in the peripheral hematopoietic tissues [10,28]; (e) in vitro the stem cell cultures show normal growth in colonies, maturing into granulocytes [29]; (f) the proliferating blast cells show phenotypes of megakaryocytic lineage [16,27,29].…”

Down's syndrome with myelodysplastic syndrome showing t(7;11)(p13;p14)

“…AML and MDS in DS often demonstrate additional chromosomal abnormalities other than constitutional trisomy 21 [8][9][10][11]. They include both numerical and structural abnormalities, but most involve complete or partial trisomy of a specific chromosome, and reciprocal translocation is relatively rare.…”

Leukaemoid reaction with megakaryocytic features in newborns with Down's syndrome

“…Constitutional abnormalities of chromosome 21 were present in 4 cases (3 had trisomy 21 and 1 a ringed 21 chromosome) and clonal abnormalities in 3 (trisomy 21 together with other chromosomal alterations). Moreover, another case recently described (9) showed the association between AMKL and Down's syndrome.…”