BACKGROUND: Blast transformation is a rare but well-recognized event in Philadelphia-negative myeloproliferative neoplasms associated with a poor prognosis. Secondary acute myeloid leukemias evolving from myeloproliferative neoplasms are characterized by a unique set of cytogenetic and molecular features distinct from de novo disease. t(8;21) (q22;q22.1); RUNX1::RUNX1T1, one of the most frequent cytogenetic abnormalities in de novo acute myeloid leukemia, is rarely observed in post-myeloproliferative neoplasm acute myeloid leukemia. Here we report a case of secondary acute myeloid leukemia with t(8;21) evolving from JAK2-mutated essential thrombocythemia.
METHODS: The patient was a 74-year-old Japanese woman who was referred because of thrombocytosis (platelets 1046 × 109/L). Bone marrow was hypercellular with increase of megakaryocytes. Chromosomal analysis presented normal karyotype and genetic test revealed JAK2 V617F mutation. She was diagnosed with essential thrombocythemia. Thrombocytosis had been well controlled by oral administration of hydroxyurea; 2 years after the initial diagnosis with ET, she presented with leukocytosis (white blood cells 14.0 × 109/L with 82% of blasts), anemia (hemoglobin 91 g/L), and thrombocytopenia (platelets 24 × 109/L). Bone marrow was hypercellular and filled with 80% of myeloperoxidase-positive blasts bearing Auer rods. Chromosomal analysis revealed t(8;21) (q22;q22.1) and flow cytometry presented positivity of CD 13, 19, 34, and 56. Molecular analysis showed the coexistence of RUNX1::RUNX1T1 chimeric transcript and heterozygous JAK2 V617F mutation in leukemic blasts. She was diagnosed with secondary acute myeloid leukemia with t(8;21)(q22;q22.1); RUNX1::RUNX1T1 evolving from essential thrombocythemia. She was treated with combination chemotherapy with venetoclax and azacytidine. After the first cycle of the therapy, blasts disappeared from peripheral blood and decreased to 1.4% in bone marrow. After the chemotherapy, RUNX1::RUNX1T1 chimeric transcript disappeared, whereas mutation of JAK2 V617F was still present in peripheral leukocytes.
CONCLUSIONS: To our best knowledge, the present case is the first one with JAK2 mutation preceding the acquisition of t(8;21). Our result suggests that t(8;21); RUNX1::RUNX1T1 can be generated as a late event in the progression of JAK2-mutated myeloproliferative neoplasms. The case presented typical morphological and immunophenotypic features associated with t(8;21) acute myeloid leukemia.

Essential thrombocythemia (ET) is a myeloproliferative neoplasm characterized by persistent elevation of platelet count due to abnormal proliferation of megakaryocytes. While some cases may be asymptomatic, the condition is associated with an increased risk of complications such as thrombosis and bleeding tendencies, necessitating appropriate management tailored to individual cases. Hemostasis analyzer systems are automated analytical devices designed for comprehensive evaluation of blood coagulation function. These systems enable rapid and accurate measurement of multiple parameters, including coagulation time, platelet function, and fibrin formation, thus facilitating a holistic assessment of hemostatic function. A 76-year-old male patient presented to our hospital. At the age of 65, he received treatment for promyelocytic leukemia and achieved remission. At 75 years, he developed leukocytosis, thrombocytosis, and progressive anemia. A comprehensive examination, including bone marrow biopsy and genetic testing, revealed a JAK2 mutation, leading to the diagnosis of ET. At the age of 76 years, he complained of chest discomfort during exertion. Further investigation revealed severe aortic valve stenosis and two-vessel coronary artery disease. The patient underwent aortic valve replacement and three-vessel coronary artery bypass grafting. A hemostasis analyzer system was used to monitor coagulation function throughout the procedure. Compared with the normal range, his coagulation profile showed a tendency toward hypercoagulability. Intraoperative and postoperative transfusions were performed as required. The patient\'s postoperative course was uneventful without any complications related to bleeding or thrombosis.

Acute myeloid leukemia (AML) is a heterogeneous hematological malignancy associated with various combinations of gene mutations, epigenetic abnormalities, and chromosome rearrangement-related gene fusions. Despite the significant degree of heterogeneity in its pathogenesis, many gene fusions and point mutations are recurrent in AML and have been employed in risk stratification over the last several decades. Gene fusions have long been recognized for understanding tumorigenesis and their proven roles in clinical diagnosis and targeted therapies. Advances in DNA sequencing technologies and computational biology have contributed significantly to the detection of known fusion genes as well as for the discovery of novel ones. Several recurring gene fusions in AML have been linked to prognosis, treatment response, and disease progression. In this report, we present a case with a long history of essential thrombocythemia and hallmark CALR mutation transforming to AML characterized by a previously unreported AKAP9::PDGFRA fusion gene. We propose mechanisms by which this fusion may contribute to the pathogenesis of AML and its potential as a molecular target for tyrosine kinase inhibitors.

Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder that is often underdiagnosed. AVWS typically occurs in adults without a family history of bleeding disorders and with associated conditions such as lymphoproliferative, myeloproliferative, and cardiovascular disorders. Here, we present a case of AVWS in a young patient with essential thrombocythemia and a literature review on AVWS in the setting of essential thrombocythemia.

Due to the thrombohemorrhagic potential of essential thrombocythemia, pregnancy complicated by essential thrombocythemia should be recognized as a risk factor for obstetric complications. Here, we report the case of a patient with essential thrombocythemia with two significantly different pregnancy outcomes. Her first pregnancy (at 30 years of age) ended with an uneventful term delivery. However, the patient progressed to cavernous transformation of the portal vein in the period between her two pregnancies and subsequently experienced deep venous thrombosis during the first trimester of her second pregnancy (at 36 years of age). The patient\'s platelet count during pregnancy was within the normal range, so she ignored previous instances of essential thrombocytosis (at 26 years of age). The patient\'s main symptom was unrelieved pain in her leg. After that, she was successfully treated with anticoagulant throughout her entire pregnancy, resulting in a term vaginal delivery. This case highlights the importance of assessing pregnant patients with essential thrombocythemia according to their risk stratification. Specifically, risk assessments for potential pregnancy complications should take into account advanced maternal age and a previous history of thrombosis. Patients with essential thrombocythemia should be encouraged to participate in preconception counseling for risk assessment and to initiate prophylactic anticoagulation as soon as possible.

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This article explores the rare case of an 82-year-old man diagnosed concurrently with essential thrombocythemia and smoldering multiple myeloma (SMM). The limited existing literature on individuals harboring both myeloproliferative neoplasm (MPN) and monoclonal gammopathy (MG) is of significant interest due to the distinct origins of these malignancies. The etiology of MG in MPN patients remains elusive, leading to speculation about a potential relationship or interplay between the two conditions. This unique case prompts a deeper exploration of the mechanisms underlying the coexistence of JAK2-positive MPN and SMM. It underscores the importance of tailored therapeutic strategies that carefully consider the inherent risks and potential adverse outcomes associated with these specific malignancies, thereby warranting further clinical research.

UNASSIGNED: Essential Thrombocythemia is a chronic myeloproliferative neoplasm characterized by an isolated excessive production of platelets. Extreme thrombocytosis is defined by having a platelet count greater than or equal to 1,000 x 109/L, which may lead to the development of acquired von Willebrand syndrome and complications of excessive hemorrhage.
UNASSIGNED: A 74-year-old female patient was brought in for a bone marrow examination regarding elevated platelet count. She had no history of excessive bleeding. The physical exam was unremarkable with no petechiae or hematomas. Complete blood count showed platelet count 1,491x109/L. Bone marrow aspiration and biopsy were unremarkable, however, the patient developed bleeding from the biopsy site. Local pressure and an ice pack were ineffective, so she received 20 mcg of desmopressin subcutaneously, 1 unit of fresh frozen plasma and was started on tranexamic acid 1,000 mg orally every 8 hours. She was admitted for bleeding control and had another dose of desmopressin. Blood work showed elevated partial thromboplastin time and normal international normalized ratio. Acquired von Willebrand syndrome was suspected and a sample for von Willebrand disease was sent out. The next day her bleeding continued, and her Hb decreased from 145 to 89 g/L, she became symptomatic (tachycardic) and fatigued. The coagulation profile was consistent with acquired von Willebrand syndrome. Since she continued bleeding, she received 1 unit of packed red blood cells. A high dose of hydroxyurea (3g/day) was started urgently; within 24 hours platelet count was halved, and the bleeding resolved. Blood work was repeated 24 hours later and showed normalization of partial thromboplastin time and a normal Von Willebrand profile.
UNASSIGNED: Patients with extreme thrombocytosis are at high risk of bleeding due to acquired Von Willebrand Syndrome. Initiation of hydroxyurea at the time of bone marrow exam helps to control platelet count and minimizes the risk of peri-procedural hemorrhage in high-risk Essential Thrombocythemia patients with suspected acquired Von Willebrand Syndrome.

UNASSIGNED: Essential thrombocythemia (ET) is a rare chronic myeloproliferative hematologic disorder, leading to an elevated platelet count. Two-thirds of patients are asymptomatic during their lifetime, while others may experience symptoms like redness, congestion, and erythromelalgia after long symptom-free intervals.
UNASSIGNED: The authors present a rare instance of a 55-year-old female who, despite receiving aspirin and losartan treatment, eventually developed digital gangrene. In further work-ups, she had an elevated platelet count and a positive JAK 2 mutation. Her platelet count was reduced throughout treatment with aspirin, hydroxyurea, and heparin, which was followed by the necrotic tip of her index finger being surgically debrided.
UNASSIGNED: Significant symptoms, such as severe acrocyanosis and even peripheral gangrene, can be treated with a single dose of aspirin. Daily aspirin consumption withstanding, this case developed the severe form of ET. In addition, while thrombocytosis predisposes patients to thrombotic complications in theory, there is little evidence to support a correlation between absolute platelet count and thrombosis.
UNASSIGNED: The initial symptom of ET could be such severe and uncommon that may develop arterial acral thrombosis despite previous daily low-dose aspirin consumption.

UNASSIGNED: Hydroxyurea is a cytotoxic drug commonly used to treat various myeloproliferative disorders. However, prolonged oral administration of this drug may trigger skin side effects and ulcers. There are few clinical reports on treating leg ulcers caused by hydroxyurea and even fewer clinical reports on managing recurrent ulcers after treatment.
METHODS: An 87-year-old woman with essential thrombocythemia presented with a painful skin ulcer on her left calf. After failed outpatient treatment, she opted for hospitalisation for free skin grafting. Four months later, ulcers reappeared at the transplant site, leading to her readmission to the hospital. The diagnosis revealed that the leg ulcers were caused by hydroxyurea. Despite this, she persisted with hydroxyurea treatment and subsequently underwent posterior tibial artery perforator flap surgery. During the two-year follow-up, a new ulcer developed on the medial condyle of her other calf. However, no new ulcers or local pain were observed in the area where perforator flap grafting was performed.
UNASSIGNED: Leg ulcers caused by hydroxyurea are rare clinically and can easily be misdiagnosed. There is currently minimal research on ulcer recurrence after treatment. Posterior tibial perforator flaps may more effectively promote the healing of recurrent ulcers.
CONCLUSIONS: Compared to conservative treatment and skin grafting surgery, the posterior tibial artery perforator flap offers a dependable blood supply and enhances the likelihood of wound healing. It can be considered an option, particularly for recurrent and refractory ulcers, even without discontinuing medication.