Tetraploid/near-tetraploid acute promyelocytic leukaemia with double (15;17) translocation

@#A 57-year-old man presented with intermittent fever and bleeding following dental surgery. Peripheral smear and bone marrow aspirate exhibited unusually large and bizarre-looking abnormal cells which were found to be myeloblasts with aberrant CD56 and CD2 expression on immunophenotyping. Fluorescence in situ hybridization analysis revealed an extra RARA gene rearrangement. This finding correlated well with a near-tetraploid karyotype with double t(15;17)(q22;q21). Bcr-3 type PML/ RARA copies were identified in reverse transcriptase-polymerase chain reaction. The diagnosis of near-tetraploid acute promyelocytic leukaemia (APML) was established. The patient was treated with all-trans retinoic acid and idarubicin and six weeks later achieved complete remission. Tetraploid/ near-tetraploid APML is exceedingly rare. It is a distinct cytogenetic subgroup with unique clinical and biological features as highlighted by atypical morphology, frequent CD2 expression and association with the bcr-3 type PML/RARA fusion transcripts. Early recognition of this rare entity is essential for timely and appropriate treatment.

Chromosomal Abnormalities in Myelodysplastic Syndrome with Near-tetraploidy: A Case Report

Massive hyperdiploidy and tetraploidy are rare cytogenetic abnormalities in myelocytic malignancies, especially in myelodysplastic syndrome (MDS). These abnormalities are known to be associated with leukemogenesis, leukemic transformation and poor prognosis. We report here the first case of MDS with near-tetraploid cytogenetic abnormality in Korea. A 80-yr-old male was diagnosed with refractory anemia with excess blasts-2 (RAEB-2). Bone marrow aspiration smear showed 16% of blasts, which were large sized myeloid blasts with irregular margins and cytoplasmic vacuolation. Cytogenetic analysis of bone marrow cells revealed numercal and structural cytogenetic abnormalities including near-tetraploidy in 8 of 20 metaphases: 45,XY,add(1)(p36.1),del(10)(p11.2),del(11)(q13),-12,-16,der(17)t(11;17) (q13;q21),add(20)(q13.1),+mar[8]/85~90,idemx2[cp8]/46,XY[4]. After chemotherapy with decitabine, he showed pancytopenia during follow-up period and died of sepsis 14 months after the diagnosis.

Near-tetraploidy Acute Myeloid Leukemia with RUNX1-RUNX1T1 Rearrangement Due to Cryptic t(8;21) / 대한진단검사의학회지

Tetraploidy or near-tetraploidy is a rare cytogenetic abnormality found in AML, and is divided into primary and secondary forms. The secondary tetraploidy or near-tetraploidy found in AML is known to be specifically associated with t(8;21). In this case report, FISH analysis detected RUNX1-RUNX1T1 gene rearrangement in the absence of cytogenetic abnormality of t(8;21), which suggests the presence of unvailed t(8;21). This is the first case report of tetraploidy or near-tetraploidy AML with cryptic RUNX1/RUNX1T1 in Korea. Although the prognosis of tetraploidy or near- tetraploidy with t(8;21) is known to be poor, this patient shows a relatively good clinical course compared to other reported cases.