BCR-ABL positive essential thrombocythaemia: a variant of chronic myelogerous leukaemia or a distinct clinical entity: a special case report.
A 37-year-old Malay man presented initially with the clinical picture of essential thrombocythaemia (ET) without the extreme leukocytosis, marked splenomegaly and low neutrophil alkaline phosphatase characteristic of chronic myelogenous leukaemia (CML). Bone marrow examination showed massive megakaryocytic hyperplasia; cytogenetic studies showed the presence of Philadelphia chromosome. The patient was treated with hydroxyurea that resulted in reduction in the platelet count. Seventeen months later, he presented with fever associated with tender massive splenomegaly. Bone marrow finding was consistent with chronic phase CML. The presence of a rearrangement involving the major breakpoint cluster region (M-bcr) on chromosome 22 was confirmed by reverse transcriptase-polymerase chain reaction. The clinical importance of finding the Philadelphia chromosome in patients who seem to have ET is in assessing prognosis. ET generally follows a chronic, indolent course. However, this patient who had Philadelphia chromosome underwent clinical transition to chronic phase CML17 months and blast crisis 29 months after presentation.
Fadilah
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SA
Division of Haematology, Department of Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia (UKM), Jalan Tenteram, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur, Malaysia.
Cheong
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SK
D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001707:Biopsy, Needle; D001853:Bone Marrow / Q000473:pathology; D003937:Diagnosis, Differential; D005500:Follow-Up Studies; D016044:Fusion Proteins, bcr-abl / Q000097:blood*; D006801:Humans; D006918:Hydroxyurea / Q000627:therapeutic use; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000175:diagnosis* / Q000188:drug therapy / Q000235:genetics; D008297:Male; D010677:Philadelphia Chromosome; D012720:Severity of Illness Index; D012846:Singapore; D013922:Thrombocytosis / Q000175:diagnosis* / Q000188:drug therapy / Q000235:genetics
D016044:Fusion Proteins, bcr-abl; D006918:Hydroxyurea