Ivanov Stanislav, Sharma Purva, Jobanputra Yash, Zhang Yuanming
University of Miami/JFK Medical Center GME Consortium Internal Medicine Residency Program, Atlantis, FL 33467, USA.
J Med Cases. 2020 Aug;11(8):239-242. doi: 10.14740/jmc3511. Epub 2020 Jul 21.
Chronic myeloid leukemia (CML) is a myeloproliferative disorder with clonal proliferation of all myeloid cell lines. The disease typically manifests in three phases: chronic course followed by an accelerated phase and finally a terminal blast crisis. A blast crisis is defined as the presence of > 20% blasts in the peripheral blood or bone marrow. The blasts could be characterized as either myeloid (60-80% of cases) resulting in acute myeloblastic leukemia or lymphoid (20-30% of cases) resulting in acute lymphoblastic leukemia. In rare instances, a blast crisis could present with biphenotypic expression for both myeloid and lymphoid blasts. In such cases, about 6-10% of the time, the course of the disease is more aggressive and renders a poorer prognosis especially if there is evidence of extramedullary involvement. We present a case of a 41-year-old woman with history of CML who presented with acute biphenotypic blast crisis with extramedullary involvement in the context of aggressive chemotherapy. Literature review reveals < 10 reported cases of CML with biphasic transformation and only three cases of CML with acute leukemia on presentation. Most cases described are in pediatric patients with varied presentations and none involving extramedullary sites. Mortality rates in such cases are near 100% despite aggressive chemotherapy.
慢性髓系白血病（CML）是一种骨髓增殖性疾病，所有髓系细胞系均发生克隆性增殖。该疾病通常表现为三个阶段：慢性病程，随后进入加速期，最终发展为终末期原始细胞危象。原始细胞危象定义为外周血或骨髓中原始细胞>20%。这些原始细胞可分为髓系（60-80%的病例），导致急性髓系白血病，或淋巴系（20-30%的病例），导致急性淋巴细胞白血病。在罕见情况下，原始细胞危象可表现为髓系和淋巴系原始细胞的双表型表达。在这种情况下，约6-10%的时间里，疾病进程更具侵袭性，预后较差，尤其是如果有髓外受累的证据。我们报告一例41岁有慢性髓系白血病病史的女性患者，在积极化疗的情况下出现急性双表型原始细胞危象并伴有髓外受累。文献综述显示，报告的慢性髓系白血病双相转化病例<10例，初诊时为慢性髓系白血病伴急性白血病的病例仅3例。描述的大多数病例为儿童患者，表现各异，且均未涉及髓外部位。尽管进行了积极化疗，此类病例的死亡率仍接近100%。
