A tetraploid minimally differentiated acute myeloblastic leukemia with extensive erythrophagocytosis: a case report and literature review

Abstract

Tetraploidy is a rare chromosome number aberration in de novo acute myeloid leukemia (AML), and may be associated with erythrophagocytosis by leukemic blast cells. We report a 48-year-old female patient with minimally differentiated acute myeloblastic leukemia (AML-M0) exhibiting tetraploidy and erythrophagocytosis. The karyotype was 46,XX[2]/92,XXXX[18]. Bone marrow aspirate smears showed large and prominent nuclei, with erythrophagocytosis in leukemic cells. Fluorescence in situ hybridization using RUNX1 dual color break probes detected four fusion signals, accounting for 95 % (190/200), in one interphase nucleus. The mutations of TP53 and the fusion genes RUNX1/ETO, CBFβ/MYH11, and PML/RARα were all negative. This patient showed a poor response to chemotherapy, and died 66 days after the onset. To our knowledge, this is the first reported case of AML-M0 with tetraploidy and erythrophagocytosis and without additional chromosome aberrations. This case of tetraploid AML with poor prognosis suggests that further biological study of more cases of tetraploid AML will be of great importance in improving the understanding and prognosis of this tetraploid AML.

Tetraploidy/near-tetraploidy acute myeloid leukemia

“…Other features, such as cytoplasmic vacuoles, irregular nuclear contour/nuclear budding, and background myelodysplasia, observed in a subset of patients, also have been described by others [2,6,7,10]. Erythrophagocytosis, described in several cases previously [26,27,23], was not an obvious finding in this study. Cytoplasmic inclusions, observed in 14 cases in this cohort, were reported by one earlier study [2].…”

A near tetraploid clone in acute myeloid leukemia with CD56 expression

“…The abnormality is rare and described in 0.98-1.2% of all AML patients. [4][5][6] Until date, less than 70 cases have been described in the literature. [6,7] Our finding is consistent with the low frequency of near tetraploidy/tetraploidy in AML.…”

“…A global defect in cell cycle control may lead to endoreduplication or nuclear mitotic division, but the exact mechanism is not yet known. [6] Near tetraploidy has been reported to be associated with different morphological French-American-British subtypes of AML and with large bizarre blasts. [4,5,7] Although DNA content was not evaluated in the present case, Kwong and Wong (1995) demonstrated that in hyperdiploid myeloid leukemias, increase in DNA content is accompanied by a corresponding increase in blast size.…”

Near Tetraploidy Acute Myeloid Leukemia in Long-term Remission with Persistent Clonal Hematopoiesis with del(20)(q12q13)

“…A bone marrow study performed in late February showed no persistent leukemic blasts or myelodysplasia. A CR was achieved morphologically; however, a chromosomal analysis of the marrow cells showed 46,XY,del(20)(q12q13) [14]/46,XY [6] (Table). Clonal hematopoiesis was considered to exist without myelodysplastic changes.…”

“…Near-tetraploidy/tetraploidy (NT/T)-AML has been reported to occur preferentially in elderly male patients and is morphologically characterized by very large blasts (2,3). Some cases have been reported to be associated with extensive erythrophagocytosis by leukemic blasts (4)(5)(6). Cases of NT/T-AML generally show a dismal prognosis, and the median overall survival (OS) is reported to be 5-9 months (1-3).…”