UNASSIGNED: Clinical presentation of leukemia cutis (LC) is polymorphic and can reveal a malignant hemopathy. More commonly described in cases of acute myeloid leukemia (AML), LC can also occur in case of chronic myeloid leukemia (CML).
UNASSIGNED: Leukemia cutis is a rare form of extramedullary feature of malignant hemopathy, seldom associated with CML. Its clinical presentation is pleiotropic and differential diagnosis is broad. It relies on clinical and typical histological and biomolecular concordance. Once confirmed, treatment is based on that of the primary condition. We present a case of a leukemia cutis revealing a relapse of a CML successfully treated by tyrosine kinase inhibitor.

A 66-year-old male presented with hypereosinophilia, thrombocytosis, extensive thrombosis refractory to direct oral anticoagulant therapy, and evidence of end-organ damage, including rash, splenic infarcts, and pulmonary infiltrates. Bone marrow biopsy revealed myeloid malignancy consistent with both chronic eosinophilic leukemia and myelodysplastic/myeloproliferative neoplasms (MDS/MPN) with SF3B1 mutation and thrombocytosis. Next-generation sequencing of the patient\'s eosinophils and neutrophil compartments revealed pathologic variants in EZH2 and SF3B1 in addition to a noncanonical JAK2 R683S mutation that has not been previously described in myeloproliferative disorders or other chronic myeloid neoplasms. These mutations were not present in the patient\'s lymphoid cell fraction, suggesting that the hematopoietic malignancy arose in a myeloid-committed progenitor cell. Based on this case and previous work from our group, we propose that noncanonical JAK2 mutations may permit signal transduction that biases toward eosinophilic differentiation in chronic myeloid neoplasms. Although the patient\'s blood counts initially responded to ruxolitinib and hydroxyurea, the response was not durable. Early referral for allogenic bone marrow transplant appears necessary to prevent long-term complications and disease progression in myeloid neoplasms with clonal hypereosinophilia driven by noncanonical JAK2 mutations.

ETV6-ABL1 gene fusion is a rare genetic rearrangement in a variety of malignancies, including myeloproliferative neoplasms (MPN), acute lymphoblastic leukemia (ALL), and acute myeloid leukemia (AML). Here, we report the case of a 16-year-old male diagnosed with a MPN, 7 months post-completion of treatment for Burkitt leukaemia. RNA sequencing analysis confirmed the presence of an ETV6-ABL1 fusion transcript, with an intact, in-frame ABL tyrosine-kinase domain. Of note, secondary ETV6-ABL1-rearranged neoplastic diseases have not been reported to date. The patient was started on a tyrosine kinase inhibitor (TKI; imatinib) and, subsequently, underwent a 10/10 matched unrelated haematopoietic stem cell transplant. He is disease-free five years post-transplant. Definitive evidence of the prognostic influence of the ETV6-ABL1 fusion in haematological neoplasms is lacking; however, overall data suggest that it is a poor prognostic factor, particularly in patients with ALL and AML. The presence of this ETV6-ABL1 fusion should be more routinely investigated, especially in patients with a CML-like picture. More routine use of whole-genome and RNA sequencing analyses in clinical diagnostic care, in conjunction with conventional cytogenetics, will facilitate these investigations.

Myelofibrosis is a BCR-ABL1-negative chronic myeloproliferative neoplasm that includes primary myelofibrosis, post-polycythemia vera myelofibrosis, and post-essential thrombocythemia myelofibrosis. It is characterized by stem cell-derived clonal proliferation that is often, but not always, accompanied by somatic mutations, which are classified into driver mutations (JAK2, CALR, or MPL), subclonal mutations and fibrosis on bone marrow biopsy. Myelofibrosis commonly demonstrates splenomegaly, constitutional symptoms, anemia, thrombocytosis, or thrombocytopenia. Patients may also be asymptomatic. Complications as thromboembolic or hemorrhagic events can reveal the disease. Primary myelofibrosis is the least common myeloproliferative neoplasm but is associated with poor survival and acute leukemic transformation. In contrast to the significant progress made in understanding the disease\'s pathogenesis, treatment for myelofibrosis remains largely palliative. The JAK2 inhibitor, ruxolitinib is not sufficient in eliminating the underlying myeloid progenitor clone, as disease inevitably returns with therapy discontinuation. Allogeneic hematopoietic stem cell transplantation is the only therapeutic option that offers potential cure. The development of novel treatment strategies aimed at slowing or even reversing disease progression, prolonging patient survival and preventing evolution to blast-phase are still lacking.

Lenalidomide is efficient in reducing red blood cell transfusion dependency and markedly lowering platelet counts in MDS/MPN-RS-T in the context of major platelet counts.

Leukemoid reaction and myeloproliferative syndrome are close mimickers and frequently pose a diagnostic dilemma, particularly when the leukocyte count is very high. Leukocyte alkaline phosphatase score frequently aids in diagnosis but may or may not be contributory, especially in differentiating chronic neutrophilic leukemia. Herein, we document a case of leukemoid reaction with extensive hyperleukocytosis in a 46-year-old female with poorly differentiated carcinoma. The tumor itself as well as the associated leukocytosis portends a poor prognosis.

Objective: To investigate the clinic-pathological features, diagnosis and treatment of 8p11 myeloproliferative syndrome (EMS) . Methods: Five patients diagnosed as EMS from Jan 2014 to May 2018 at Blood Disease Hospital, Chinese Academy of Medical Sciences were enrolled. The clinical manifestations, laboratory characteristics, treatment and outcome of these patients were summarized. Results: The peripheral blood leukocyte count of 5 patients with EMS increased significantly, accompanied with an elevated absolute eosinophils value (the average as 18.89×10(9)/L) . The hypercellularity of myeloid cells was common in bone marrow, always with the elevated proportion of eosinophils (the average as 17.24%) , but less than 5% of blast cells. The chromosome karyotype of the 5 cases differed from each other, but presenting with the same rearrangement of FGFR1 gene by fluorescence in situ hybridization technology. The average interval between onset and diagnosis was 4.8 months with a median survival of only 14 months. Conclusion: EMS was a rare hematologic malignancy with poor prognosis and short survival. It was commonly to be misdiagnosed. Analysis of cytogenetics and molecular biology were helpful for early diagnosis.
目的： 分析罕见疾病伴嗜酸性粒细胞增多和FGFR1重排的髓系/淋系肿瘤（即8p11骨髓增殖综合征，EMS）的临床特征、诊断及治疗。 方法： 总结中国医学科学院血液病医院2014年1月至2018年5月收治的5例确诊EMS患者的临床表现、实验室特征、诊治经过及转归。 结果： 5例EMS患者外周血白细胞计数均明显升高，伴有嗜酸性粒细胞绝对值增高（均值18.89×10(9)/L）；骨髓髓系极度增生，原始细胞均<5%，嗜酸性粒细胞比例增高（均值17.24%）。5例患者染色体核型各不相同，但FISH检查均存在FGFR1基因重排。发病至确诊平均时间为4.8个月，中位生存期仅14个月。 结论： EMS是一种罕见病，恶性程度高，对常规化疗反应差，生存期短，且易发生误诊漏诊，细胞遗传学及分子生物学检查有助于早期诊断。.

BACKGROUND: Cerebral salt wasting (CSW) is a rare metabolic disorder with severe hyponatremia and volume depletion usually caused by brain injury like trauma, cerebral lesion, tumor or a cerebral hematoma. The renal function is normal with excretion of very high amounts of sodium in the urine. Diagnosis is made by excluding other reasons for hyponatremia, mainly the syndrome of inappropriate antidiuretic hormone secretion (SIADH).
METHODS: A 60-year-old patient was admitted to the emergency room with pain in the upper abdomen and visual disturbance two weeks after knee replacement. The patient was confused with severe hematoma at the site of the knee endoprosthesis. Laboratory values showed massive thrombocytosis, leukocytosis, anemia, severe hyponatremia and no evidence of infection. CT scan of the abdomen was inconspicuous. Head MRI showed no ischemia or bleeding, but a mild microangiopathy. A myeloproliferative neoplasm (MPN) was suspected and confirmed by bone marrow biopsy. Cerebral salt wasting syndrome was identified as the cause of severe hyponatremia most likely provoked by cerebral microcirculatory disturbance. The hematoma at the operation site was interpreted as a result of a secondary von Willebrand syndrome (vWS) due to the myeloproliferative neoplasm with massive thrombocytosis. After starting cytoreductive therapy with hydroxycarbamide, thrombocytosis and blood sodium slowly improved along with normalization of his mental condition.
CONCLUSIONS: To the best of our knowledge this is the first description of a patient with CSW most likely caused by a microcirculatory disturbance due to a massive thrombocytosis in the context of a myeloproliferative neoplasm.

Hydroxyurea (HU) is a drug frequently used in the treatment of chronic myeloproliferative neoplasms. The most common side effects of this drug are pancytopenia, digestive and skin disorders. Respiratory complications are rare and there are less than 20 cases described, only 5 of which underwent an anatomopathological study. We present the case of a patient with chronic myeloproliferative neoplasm who developed interstitial pneumonitis probably due to HU according to histological study.

Myelodysplasia (MDS) /myeloproliferative neoplasm (MPN) overlap syndrome has been described since the 2001 WHO classification as disorders that have both proliferative and dysplastic changes simultaneously. Specific disorders include chronic myelomonocytic leukemia (CMML), juvenile myelomonocytic leukemia (JMML), BCR-ABL negative atypical chronic myeloid leukemia (aCML) and unclassifiable MDS/MPN (MPN/MDS-U). Recurrent gene mutations in these conditions have been described. Among them, SETBP1 mutations have been identified in up to 32% of aCML, 24% of JMML, 18% of CMML and 10% of MDS/MPN-U patients. The mutation hotspot lies in the amino acid residues 858-871 in the SETBP1 protein. SETBP1 mutations in MDS/MPN overlap syndrome is associated with accelerated transformation to leukemia and poor prognosis. In this review, we summarized the latest data on the role of SETBP1 mutations in the overlap syndrome. SETBP1 mutations may serve as a biomarker for the diagnosis and poor prognosis of the overlap syndrome.