中国生物工程杂志

Objective: To investigate the clinical and laboratory features of chronic myelogenous leukemia with marked thrombocytosis (CML-T), and analyze the key points of differentiation from essential thrombocythemia (ET). Methods: By reviewing 15 patients with CML-T admitted to our hospital from January 2013 to January 2023 and 15 randomly selected patients with ET during the same period, we analyzed and compared their clinical manifestations and related laboratory results. Results: The CML-T group presented significantly elevated platelet counts up to 2 387 × 10⁹/L. Meanwhile, the BCR∷ABL1 fusion gene was detected in all CML-T patients, and all of them were of the p210 type. Compared with the ET group, the CML-T group had a higher white blood cell (WBC) count, basophil percentage and mean platelet volume (MPV), as well as a higher prevalence of immature granulocytes in the PB smear, with all P values < 0.05. On bone marrow aspiration examination, the CML-T group presented a higher degree of hyperplasia, a higher myeloid-erythroid ratio, a higher number of megakaryocytes, a smaller mean diameter of megakaryocytes, and a more severe myelofibrosis grading, with all P values <0.05. Conclusions: CML-T has an insidious onset, with only elevated PLT count, normal or mildly elevated WBC count, occasional immature granulocytes in the PB, and rare splenomegaly, making it easy to be misdiagnosed as ET. When the PLT count is significantly higher with an increased percentage of basophils, increased MPV and the presence of immature granulocytes in PB, CML-T should be screened and BCR∷ABL1 fusion gene detection should be suggested in time. In addition, the degree of bone marrow hypercellularity, high myeloid-erythroid ratio, increased megakaryocyte count, and characteristic small megakaryocyte morphology can provide important diagnostic clues to help avoid misdiagnosis and achieve early diagnosis and treatment.