[The hypereosinophilic variant of Ph'-positive chronic myeloleukemia]

To confirm clonal nature of idiopathic hypereosinophilic syndrome (IHES), its relevance to Ph'-positive chronic myeloid leukemia.

3 cases of idiopathic hypereosinophilic syndrome are reported with morphologic analysis of bone marrow cells and cytogenetic examinations. In one patient the presence of Ph'-chromosome was confirmed at fluorescent in situ hybridization (FISH) and molecular-genetic analysis (bcr/abl). Samples of bone marrow, spleen and liver were examined pathohistologically.

The presence of chromosome anomaly t(9;22), i.e. Ph'-chromosome, associated with chronic myeloid leukemia (CML) was identified in all the 3 cases. There was also myeloid hyperplasia in the bone marrow (with primarily mature, eosinophilic granulocytes), spleen and liver, depression of megakaryocyto- and erythropoiesis. 2 patients had similar clinical symptoms which was not typical for CML in chronic phase: fever, elevated ESR, clear-cut anemia and thrombocytopenia. In the absence of hyperleukocytosis, blood and bone marrow eosinophils remained high (42.5, 21.5, 42.5% and 21.4, 7.1, 6.5%, respectively) due to "mature" forms. The number of blasts in the bone marrow was maximum 2.4%.

The literature and the obtained data suggest closeness of idiopathic hypereosinophilic syndrome and Ph'-positive CML within myeloproliferative diseases.