Leukaemic Transformation in a Case of Thrombocythaemia

Abstract

The authors describe a case of thrombocythaemia, with subsequent leukaemic transformation. Cytochemical and immunocytochemical investigations indicated a trilineage involvement of the myeloid series, compatible with a leukaemic transformation at the level of the colony-forming unit granulocytes, erythrocytes, macrophages, megakaryocytes. No cytogenetic abnormalities were observed. The criteria which have been proposed to differentiate essential thrombocythaemia from pre-fibrotic thrombocythaemia, as an early phase of idiopathic myelofibrosis, are discussed. The differentiation is not only of academic interest but has relevant practical implications, since survival in the two conditions is significantly different. The possible significance of an accompanying monoclonal gammopathy is discussed.

Transition of Essential Thrombocythemia to Megakaryoblastic Leukemia after Long-Term Therapy with Sequential Busulfan, Pipobroman and Hydroxyurea

“…After reading the interesting observations of Quaglino et al [1] concerning leukemic transformation of essential thrombocythemia (ET), we would like to report a case of a megakaryoblastic leukemia in a case with long-standing (17 years) ET. In January 1984, a 54-year-old man was admitted to our hospital for persistent microvascular thrombotic episodes of the toes, with rapid progression to ulcerative and necrotic lesions.…”

“…It is important to distinguish ET from the early hypercellular stages of idiopathic myelofibrosis without relevant bone marrow fibrosis, as the survival rates are different [1]. As an extension of the Polycythemia Vera Study Group for ET [3], the new clinical and pathological WHO criteria, introducing more precisely defined diagnostic features for ET [4], raised the question of whether the cases hitherto described in the literature were ET or thrombocythemias occurring in myelofibrosis or in myeloproliferative/dysplastic syndromes.…”

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].…”

“…ET is a proliferation of multipotent hemopoietic stem cells which may evolve into acute leukemia or myelofibrosis. The incidence of leukemic transformation in patients with ET is reported to range from 0.7 to 5.3% [1].…”