Chronic eosinophilic leukaemia (CEL): a distinct myeloproliferative disease

Abstract

Chronic eosinophilic leukaemia has not yet been clearly defined, mainly due to the fact that it has not been conclusively shown as a monoclonal disease which should be separated from chronic myelogenous leukaemia, acute myelogenous leukaemia with eosinophilia (AML, FAB M4Eo), and the idiopathic hypereosinophilic syndrome. We report a patient with a white blood cell count of 17.6 × 109/l with 74% eosinophils, normal platelet count and haemoglobin. No blasts were seen in the peripheral blood and the percentage of blasts in the bone marrow was <3%. A diagnosis of chronic eosinophilic leukaemia was made. Chromosome analysis of a bone marrow aspirate disclosed a trisomy 15 together with loss of the Y chromosome. Moreover, FISH analysis on May‐Grünwald‐Giemsa‐stained peripheral blood smears demonstrated trisomy 15 in the eosinophils. 3 months after initial diagnosis the patient went into blast crisis and died. The blast cells exhibited trisomy 15 and loss of the Y chromosome in a complex, aberrant karyotype. In conclusion, the case shows that chronic eosinophilic leukaemia is a monoclonal, myeloproliferative disease with eosinophils as part of the malignant clone. Clinically, chronic eosinophilic leukaemia can be separated into a chronic phase and a blast crisis.

Targeted next-generation sequencing identifies a subset of idiopathic hypereosinophilic syndrome with features similar to chronic eosinophilic leukemia, not otherwise specified

“…Dysgranulopoiesis and dyserythropoiesis were also observed in a subset of our chronic eosinophilic leukemia, not otherwise specified cases. Reviewing the literature, although most of studies on CEL and idiopathic hypereosinophilic syndrome do not provide in detail histological descriptions, Weide et al 41 and Kuk et al 42 did describe multilineage dysplasia in their case report of chronic eosinophilic leukemia, not otherwise specified. Regarding the eosinophil morphology, we found frequent abnormalities in chronic eosinophilic leukemia, not otherwise specified and these were seen less frequently in idiopathic hypereosinophilic syndrome without mutations.…”

Imatinib therapy for hypereosinophilic syndrome and other eosinophilic disorders

“…Other cytogenetic abnormalities reported to be associated with eos-CMD, where the molecular mechanisms for disease pathogenesis have not yet been elucidated, include t(8;9)(p22;p23), t(3;9;5)(q25;q34;q33), 17 and trisomy 15. [18][19][20] Additionally, a few cases of eosinophilic-myelodysplastic syndrome, particularly therapy-related myelodysplastic syndrome, have also been described and are associated with the t(1;7) cytogenetic abnormality. 21 In our study, despite careful evaluation of 6 of 7 patients by bone marrow (BM) cytogenetic analysis and screening of most coding exons of c-kit and PDGFR␤ genes, none of the known mutations in cellular targets of imatinib (ie, bcr-abl, c-kit, or PDGFR␤ tyrosine kinases) were identified.…”

Cloning of the t(1;5)(q23;q33) in a myeloproliferative disorder associated with eosinophilia: involvement of PDGFRB and response to imatinib

“…However, this is not always true, [16][17][18] and only rarely has the clonality of the eosinophils been clearly established. 19 As seen in Figure 2, eosinophils are readily identified on the basis of the autofluorescence of eosinophilic granules, a feature that is unique among cells of the granulocytic series. [19][20][21] These granules were pseudo- Figure 1.…”

“…19 As seen in Figure 2, eosinophils are readily identified on the basis of the autofluorescence of eosinophilic granules, a feature that is unique among cells of the granulocytic series. [19][20][21] These granules were pseudo- Figure 1. PDGFRB is fused to PDE4DIP in an MPD associated with eosinophilia and t(1;5)(q23;q33).…”