Acute biphenotypic leukemia arising in a patient with essential thrombocythemia

Abstract

Acute leukemia is an uncommon complication of patients with essential thrombocythemia (ET). We describe a patient with ET, who transformed to acute biphenotypic leukemia 4 and 1/2 years after initial ET diagnosis. She had received hydroxyurea, anagrelide, and interferon, in different combinations and varying doses, before leukemic transformation. Acute biphenotypic leukemia was confirmed on bone marrow studies and immunophenotyping. Complete remission (CR) was achieved with induction chemotherapy for acute leukemia. This was followed with consolidation chemotherapy and the patient has remained in CR 9 months after initial induction chemotherapy. To our knowledge, this is a rare event of acute biphenotypic leukemic transformation of a patient with ET. Am. J. Hematol. 81:624-626, 2006. V V C 2006 Wiley-Liss, Inc.

Myeloid sarcoma in essential thrombocythemia that transformed into acute myeloid leukemia

“…In the literature, the incidence of leukemic transformation in patients with ET is reported to range from 0.7 to 5.3% [1]. Cytogenetic abnormalities, myelofibrotic features in the bone marrow and the use of cytotoxic agents, such as hydroxyurea, were reported as risk factors for leukemic transformation [7]. Our patient had neither bone marrow fibrosis nor cytogenetic abnormalities, but he had been treated with hydroxyurea for approximately 5 years.…”

“…According to WHO classification, it can be classified into three main types: blastic, immature, and differentiated [11]. It can be isolated or encountered during the course of AML, CML, MDS, or MPD [7]. It generally occurs with leukemic transformation, although two cases of ET that developed into MS without leukemic transformation have been reported [3,6].…”

Leukaemic transformation of Philadelphia chromosome‐negative myeloproliferative neoplasms: are Asian patients different?

“…Transformation to acute myeloid leukaemia is more commonly seen than that to acute lymphoblastic leukaemia, and transformation to biphenotypic leukaemia is considered rare. 8,9 In our study group, 20 out of 22 patients transformed into acute myeloid leukaemia. The other two patients transformed into biphenotypic leukaemia.…”

“…2,3,5 Most of the cases reported transformation to acute myeloid leukaemia, with only few case reports of transformation to bilineage forms. 8,9 Complex cytogenetic abnormalities are commonly found in the leukaemic cells and many poor prognostic abnormalities are described. 1 The most common cytogenetics include +1q, -5, 5q-, -7, 7q-, +8, +9, 11q-, 13q-and 20q-.…”