Acute megakaryoblastic leukaemia shows high frequency of chromosome 1q aberrations and dismal outcome.

Acute megakaryoblastic leukaemia (AMKL) is associated with poor prognosis. Limited information is available on its cytogenetics, molecular genetics and clinical outcome. We performed genetic analyses, evaluated prognostic factors and the value of allogeneic haematopoietic stem cell transplantation (allo-HSCT) in a homogenous adult AMKL patient cohort. We retrospectively analysed 38 adult patients with AMKL (median age: 58 years, range: 21-80). Most received intensive treatment in AML Cooperative Group (AMLCG) trials between 2001 and 2016. Cytogenetic data showed an accumulation of adverse risk markers according to ELN 2017 and an unexpected high frequency of structural aberrations on chromosome arm 1q (33%). Most frequently, mutations occurred in TET2 (23%), TP53 (23%), JAK2 (19%), PTPN11 (19%) and RUNX1 (15%). Complete remission rate in 33 patients receiving intensive chemotherapy was 33% and median overall survival (OS) was 33 weeks (95% CI: 21-45). Patients undergoing allo-HSCT (n = 14) had a superior median OS (68 weeks; 95% CI: 11-126) and relapse-free survival (RFS) of 27 weeks (95% CI: 4-50), although cumulative incidence of relapse after allo-HSCT was high (62%). The prognosis of AMKL is determined by adverse genetic risk factors and therapy resistance. So far allo-HSCT is the only potentially curative treatment option in this dismal AML subgroup.

Cyto-morphological features of extramedullary acute megakaryoblastic leukemia on fine needle aspiration and cerebrospinal fluid cytology: A case report.

Extramedullary deposits may be the presenting feature of acute myeloid leukemia. An early and accurate diagnosis on cytology will aid in correct patient management. This is especially true for patients with acute megakaryoblastic leukemia (AML M7), where bone marrow aspiration may yield only a dry tap. While cytomorphological features of myeloid sarcoma of other types are well recognized due to its rarity, there are only two case reports discussing the morphological details of megakaryoblastic differentiation on aspiration cytology. We present the case of a 25-year-old patient with extramedullary involvement of lymph node and cerebrospinal fluid by AML M7, describing in detail, the morphological features on aspiration as well as exfoliative cytology.

Alpha-Synuclein Expression in Acute Erythroleukaemia, Acute Megakaryoblastic Leukemia, and Normal Counterparts in Bone Marrow.

BACKGROUND: Alpha-synuclein is a member of synuclein family of proteins with unidentified function localized in the cytoplasm, mitochondria of neurons, and presynaptic nerve endings. Although it is found in the Lewy bodies in synucleinopathies and in Alzheimer's disease, the protein could also be considered as a novel marker in diagnosis of diseases related to the hematopoietic system. METHODS: The current study evaluated alpha-synuclein expression in bone marrow sections obtained from 9 patients with acute myeloblastic leukemia (AML)-M6, 2 patients with AML-M7, and 56 patients with other forms of AML by immunohistochemical (IHC) analysis. RESULTS: Seven out of 9 cases with erythroleukemia (66.7%) and 1 of the 2 cases with M7 (50%) were positive. In contrast; the blasts in 2 out of 56 AML cases with non-M6/M7 (3.6%) showed positive staining. Accordingly, alpha-synuclein was positive in normal erythroid precursors and megakaryocytes (if existing) in these cases; while, it was negative in lymphoid and myeloid precursors. CONCLUSION: Alpha-synuclein expression in non-neoplastic and neoplastic erythroid cells and megakaryocytes could be used as a complementary and useful marker for distinction between AML-M6/M7 and other types of AML.

Acute megakaryocytic leukemia: What have we learned.

Acute megakaryocytic leukemia (AMegL) is a biologically heterogenous subtype of acute myeloid leukemia (AML) that arises from megakaryocytes. Improvements in the accuracy of diagnosing AMegL as well as interest in the molecular analysis of leukemias have led to an increased amount of data available on this rare AML subtype. In this review, we will analyze the diverse molecular features unique to AMegL and how they have influenced the development of novel treatment strategies, including polyploidization. The review will also consider the data available on clinical outcomes in AMegL and how it is a poor individual prognostic factor for AML. Finally, the role of allogeneic hematopoietic stem cell transplant in AMegL will be explored.

AML M7 Misdiagnosed as ALL.

Hematogones, which are normal precursors of B lymphocytes in the bone marrow, may be mistaken for blast cells on flow cytometry and histology when their numbers increase. We report such a case in a 16 months old male who was unsuccessfully treated for a pre-B cell ALL on the basis of flow cytometry of the bone marrow which showed a substantial population of CD19 and CD10 expressing 'blast' cells. A diagnosis of AML M7 was made on a subsequent bone marrow biopsy in which the blast cells expressed CD61 and Factor VIII, while they were negative for CD10 and CD20. Also present were a few CD10 and CD20 expressing small lymphoid cells, which were interpreted as hematogones. This report reiterates the problem of mistaking hematogones for 'blast' cells on flow cytometry, especially in the marrow of very young children where hematogones are often prominent.

A case of chronic myeloid leukaemia presenting as megakaryocytic blast crisis (AML M7).

Acute megakaryocytic leukaemia (AMeL) is a rare subtype of acute myeloid leukaemia, which can be frequently misdiagnosed as acute myelofibrosis or myelosclerosis [1]. Chronic myeloid leukaemia (CML) presenting primarily as megakaryocytic blast crisis is very rare, with very few case reports published to date [2, 3]. This case report describes a 36-year-old woman who presented with anaemia and massive splenomegaly with peripheral blood and bone marrow showing features of AMeL. Reverse transcriptase polymerase chain reaction and gel-electrophoretic study of peripheral blood leucocytes demonstrated breakpoint cluster region-Abelson oncogene translocation encoding for p210 fusion protein. Megakaryocytic blast crisis as the primary presentation of CML is very rare and requires clinical correlation and additional cytogenetic studies to determine the diagnosis.