Tetraploid acute promyelocytic leukemia with double t(15;17) and PML/RARA rearrangements detected by fluorescence in situ hybridization analysis

Tetraploid acute promyelocytic leukemia with double translocation t (15,17) PML/RARA: the first case report in Croatia and Europe

Acute promyelocytic leukemia (APL) is characterized by the translocation t (15;17)(q22;q21) cytogenetic abnormality in the majority of cases. In most of the cases the cells of APL have normal, diploid karyotype. There are very few cases presented with very rare tetraploid karyotype with double translocation t(15;17)(q22;q12). We report the first case of tetraploid APL with double translocation t(15, 17) in Europe. A 66-year old male patient presented with dyspnea and unexplained dental bleeding. Blood work showed a white blood cell count of 1x109/L, hemoglobin was 124 g/ L, platelet count was 61x109/L and fibrinogen level was low (1.4 g/L). Cytogenetics showed a tetraploid karyotype. Fluorescence in situ hybridization analysis proved existence of clonal cells with translocation t (15,17) in 15% of metaphase nuclei and tetraploid subclonal cells with the same translocation in 70% of metaphase nuclei. Findings were consistent with APL, tetraploid variant and the patient started all-trans retinoic acid (ATRA) treatment. The patient achieved complete remission in 2 months and completed three consolidation therapy cycles with ATRA, idarubicin or mitraxontrate. Currently, the patient is undergoing maintenance therapy with ATRA, 6-mercaptopurine and weekly methotrexate.

Tetraploidy with double t(11;18) of recurrent MALT lymphoma in buccal mucosa: a case report

Mucosa-associated lymphoid tissue (MALT) lymphoma is a type of an extranodal marginal zone B-cell lymphoma that accounts for about 5% to 8% of all B-cell lymphomas. It is rare for a recurrent oral MALT lymphoma to have tetraploidy with a double t(11;18) chromosomal abnormality, however. A 66-year-old Japanese woman with a swelling of the right buccal mucosa was referred to our hospital. A tumor was excised, and a pathologic diagnosis of MALT lymphoma with a t(11;18) (q21; q21) chromosome translocation was made. Two years later, swelling of the right buccal mucosa recurred, which was then excised and pathologically diagnosed as MALT lymphoma. This tumor did not have a t(11;18) (q21; q21) chromosome translocation, but exhibited tetraploidy with double t(11;18). FISH analysis revealed that the recurrent MALT lymphoma of the buccal mucosa had tetraploidy with double t(11;18). This is the first reported case of a recurrent MALT lymphoma showing tetraploidy with double t(11;18).

CD2+ tetraploid acute promyelocytic leukemia variant with double (15;17) translocations

We report a patient with a variant form of CD2+ acute promyelocytic leukemia (APL) who had double translocations (15;17) in a single leukemic cell. The patient presented with severe neutropenia, thrombocytopenia, and disseminated intravascular coagulation. The bone marrow showed marked hyperplasia with large leukemic cells that had bizarre nuclear configuration and basophilic, hypogranular cytoplasm. Leukemic cells were positive for CD2, 13, 33, 34, and 56 and negative for HLA-DR. The karyotype of the abnormal clone was characterized as 92,XXYY, t(15;17)(q22;q21)x2. No other additional abnormal clone was found, and the patient's condition was diagnosed as tetraploid APL variant. Fluorescence in situ hybridization assay revealed 2 promyelocytic leukemia and retinoic acid receptor alpha (PML/RARA) fusion signals, and reverse transcription-polymerase chain reaction assay revealed short-form PML/RARA fusion transcript. Tetraploidy in APL is a very rare abnormality. Double translocations were an additional abnormality in this case, and this patient's karyotype might have had some influence on morphological characteristics, expression of CD2, and poor clinical outcome.