A complex t(3;8;17) involving breakpoint 8p11 in a case of M5 acute nonlymphocytic leukemia with erythrophagocytosis

Normal karyotype in a case of acute myeloid leukemia with monocytic differentiation and hemophagocytosis by leukemic blasts

We report the case of a 39-year-old woman with acute myeloid leukemia (AML) with monocytic differentiation showing hemophagocytosis by leukemic blasts. This phenomenon is known to be associated with certain chromosomal changes, including t(8;16), der(8), inv(8), and t(16;21); however, in this case, the patient had a normal female karyotype. To our knowledge, this is the first published case of normal karyotype AML with hemophagocytosis by leukemic blasts.

The leucine twenty homeobox (LEUTX) gene, which lacks a histone acetyltransferase domain, is fused to KAT6A in therapy-related acute myeloid leukemia with t(8;19)(p11;q13)

The monocytic leukemia zinc finger protein KAT6A (formerly MOZ) gene is recurrently rearranged by chromosomal translocations in acute myeloid leukemia (AML). KAT6A is known to be fused to several genes, all of which have histone acetyltransferase (HAT) activity and interact with a number of transcription factors as a transcriptional coactivator. The present study shows that the leucine twenty homeobox (LEUTX) gene on 19q13 is fused to the KAT6A gene on 8p11 in a therapy-related AML with t(8;19)(p11;q13) using the cDNA bubble PCR method. The fusion transcripts contained 83 nucleotides upstream of the first ATG of LEUTX and are presumed to create in-frame fusion proteins. LEUTX is known to have a homeobox domain. Expression of the LEUTX gene was only detected in placenta RNA by RT-PCR, but not in any tissues by Northern blot analysis. The putative LEUTX protein does not contain any HAT domain, and this is the first study to report that KAT6A can fuse to the homeobox gene. The current study, with identification of a new partner gene to KAT6A in a therapy-related AML, does not elucidate the mechanisms of leukemogenesis in KAT6A-related AML but describes a new gene with a different putative function.

Acute myeloid leukaemia with 8p11 (MYST3) rearrangement: an integrated cytologic, cytogenetic and molecular study by the groupe francophone de cytogénétique hématologique

Thirty cases of acute myeloid leukaemia (AML) with MYST histone acetyltransferase 3 (MYST3) rearrangement were collected in a retrospective study from 14 centres in France and Belgium. The mean age at diagnosis was 59.4 years and 67% of the patients were females. Most cases (77%) were secondary to solid cancer (57%), haematological malignancy (35%) or both (8%), and appeared 25 months after the primary disease. Clinically, cutaneous localization and disseminated intravascular coagulation were present in 30 and 40% of the cases, respectively. AMLs were myelomonocytic (7%) or monocytic (93%), with erythrophagocytosis (75%) and cytoplasmic vacuoles (75%). Immunophenotype showed no particularity compared with monocytic leukaemia without MYST3 abnormality. Twenty-eight cases carried t(8;16)(p11;p13) with MYST3-CREBBP fusion, one case carried a variant t(8;22)(p11;q13) and one case carried a t(8;19)(p11;q13). Type I (MYST3 exon 16-CREBBP exon 3) was the most frequent MYST3-CREBBP fusion transcript (65%). MYST3 rearrangement was associated with a poor prognosis, as 50% of patients deceased during the first 10 months. All those particular clinical, cytologic, cytogenetic, molecular and prognostic characteristics of AML with MYST3 rearrangement may have allowed an individualization into the World Health Organization classification.

Translocation (8;18;16)(p11;q21;p13). A new variant of t(8;16)(p11;p13) in acute monoblastic leukemia: case report and review of the literature

A complex three-way t(8;18;16)(p11;q21;p13) was detected in a 15-month-old patient with acute myeloid leukemia (AML). The patient had typical clinical manifestation and bone marrow features of AML subtype M5b associated with t(8;16)(p11;p13). Therefore, we believe that the t(8;18;16) is a new variant of t(8;16) related to AML M4/M5. We also review other t(8;16)(p11;p13) variants reported in the literature.

Acute monoblastic leukemia with t(8;16): a distinct clinicopathologic entity; report of a case and review of the literature

We report a case of acute monoblastic leukemia with t(8;16) in a 71-year-old man who had rapid rise of leukocyte counts from 20.3 x 10(9)/l to 62.7 x 10(9)/l in two weeks. The peripheral blood showed many granular promonocytes that led to the consideration of acute promyelocytic leukemia of the hypogranular variant. The bone marrow, however, revealed mainly monoblasts with erythrophagocytosis. Cytogenetic study finally confirmed the diagnosis of acute monoblastic leukemia with t(8;16). The patient died three days after admission. The demonstration of these two characteristic features of this subtype, granular promonocytes and erythrophagocytosis by monoblasts, separately, in the peripheral blood and bone marrow is unusual and misleading. This cytogenetic abnormality can be demonstrated only in M5 and M4 with characteristic clinical features of disseminated intravascular coagulation, extramedullary involvement, and poor prognosis. Although it is not a common disease, this specific subtype of acute myelogenous leukemia is consistently associated with a specific cytogenetic marker, thus it should be considered a distinct clinicopathologic entity.

Translocation t(8;16)(p11;p13) in acute non-lymphocytic leukemia: report on two new cases and review of the literature

Two new cases of t(8;16)(p11;p13) in acute nonlymphocytic leukemia (ANLL) are described. These two patients in addition to the 34 previously described, showed a striking association with myelomonocytic (M4) or monocytic (M5) leukemia, extramedullary infiltration, erythrophagocytosis and disseminated intravascular coagulation. One of our patients showed a TCRbeta gene rearrangement. Alltogether 36 cases of t(8;16) ANLL have been documented until today. We here review their clinical and cytogenetic features.

A distinct subtype of M4/M5 acute myeloblastic leukemia (AML) associated with t(8:16)(p11:p13), in a patient with the variant t(8:19)(p11:q13)--case report and review of the literature

Acute myeloblastic leukemia (AML) with t(8:16) or its variant t(8:V) has been rarely reported. A high proportion of patients are infants and children, often with a bleeding tendency and disseminated intravascular coagulopathy (DIC). Only one-third of the de novo patients remain in the first complete remission following multiagent chemotherapy and bone marrow transplantation (BMT). Morphocytochemically, the disorder is classified as an M5, M4, or M4/M5 variant. In the presented case, with the variant t(8:19)(p11:q13), comprehensive light and electron microscopic blast cell characterization showed monocytic and granulocytic features compatible with the M4 subtype (on the monocytic predominance range of the French-American-British classification scale). Although hemophagocytosis, one of the hallmarks of the disease, was rare in our patient, numerous autophagic vacuoles were present. Immuno- and genotyping showed a myelomonocytic phenotype with no evidence of early progenitor antigen expression or mixed leukemia. These results and those of previous reports support the high specificity of t(8:16) or its variants to the unique M4/M5 type leukemia and the role of a gene on 8p11 in this specific transformation.

Acute monoblastic leukemia (FAB-M5b) with t(8;14)(p11;q11.1)

A case of acute monocytic leukemia (FAB-M5b) expressing natural killer cell-associated antigens containing a t(8;14)(p11;q11.1) is presented. We interpret this translocation to represent a variant of the t(8;16) previously reported in FAB-M5b. These findings support the contention that the 8p11 breakpoint site is the critical junction in the oncogenesis of acute monoblastic leukemia with differentiation.

Translocation (16;21)(p11;q22) in acute monoblastic leukemia with erythrophagocytosis

A patient with acute monoblastic leukemia with erythrophagocytosis and a t(16;21) (p11;q22), poor response to chemotherapy, early relapse, and a short survival of ten months is presented. Hematologically, this patient could be considered as a case of FAB M5b/t(8;16) but without the characteristic chromosomal translocation, i.e., there is no visible alteration on chromosome 8 and the breakpoint on chromosome 16 appears to be very proximal. These findings are briefly discussed in the light of other variants.