Primary Thrombocythemia in Japan: A Survey of 225 Patients

Hemorrhagic stroke associated with essential thrombocythemia: Case report and literature review

Hemorrhagic stroke associated with essential thrombocythemia (ET) is very infrequent. Herein, we report a case of a 33-year-old woman with a 2-year history of ET who developed intracerebral and subarachnoid hemorrhage. Angiography demonstrated severe vessel irregularity in the bilateral cerebral arteries. Molecular genetic testing revealed a calreticulin mutation. To our knowledge, hemorrhagic stroke has been reported in only six other patients with ET, and this is the first report of hemorrhagic stroke in an ET patient with a calreticulin mutation. We review the current literature and discuss the possible underlying mechanisms.

Multiple granulocytic sarcomas in essential thrombocythemia

A 59-year-old woman was diagnosed with essential thrombocythemia in 1988 and had been treated with hydroxyurea, mitobronitol, busulfan, and ranimustine, in that order. Hepatosplenomegaly, low-grade fever, and body weight loss manifested, and a few blasts were noted in the peripheral blood studied in March 2002. A biopsied specimen of the bone marrow showed myelofibrosis but not a leukemia in August 2004. An abnormal karyotype with der(1; 13) appeared for the first time. She was treated with low-dose prednisolone. In January 2005, she experienced left hip joint pain, and magnetic resonance scanning showed a tumoral lesion in the femoral head. Histological diagnosis of the biopsied mass revealed that it was a granulocytic sarcoma, and radiotherapy was performed. In April 2005, bone scintigraphy showed multiple lesions. She became febrile and red blood cell transfusion-dependent with hepatosplenomegaly and a small number of circulating blasts. Intravenous cytarabine (low dose) and etoposide relieved the fever and hepatosplenomegaly; however, she developed a pathologic fracture of the right humerus. An additional karyotypic abnormality (7q22 deletion) was noted. She subsequently died of infection. Granulocytic sarcoma is very rare in essential thrombocythemia, and this patient may be the first reported case of essential thrombocythemia that developed multiple lesions and a pathologic fracture without transformation to overt leukemia.

Acute myocardial infarction in a patient with essential thrombocythemia who underwent successful stenting--a case report

Essential thrombocythemia (ET) can cause systemic vascular thrombosis, but involvement of coronary arteries in the setting of ET is rare. This report describes a case of acute myocardial infarction (MI) in a patient with ET. A 67-year-old man with ET complained of severe acute chest pain. Emergent coronary angiography revealed subtotal thrombotic occlusion of the left main trunk (LMT) coronary artery. Coronary angioplasty and stenting were performed successfully. Coronary angiography 4 weeks later revealed no significant restenosis. The patient has done well after primary coronary stenting with the use of only an antiplatelet agent to treat the thrombocythemia.

De novo appearance of der(1;7)(q10;p10) is associated with leukemic transformation and unfavorable prognosis in essential thrombocythemia

Leukemic transformation or myelofibrosis is a major concern in managing patients with chronic myeloproliferative disorders, including essential thrombocythemia (ET). We analyze the relationship between cytogenetic changes and the transformation in 89 patients with ET; 8 patients experienced transformation, including 2 patients with acute leukemia following myelofibrosis, 3 with acute leukemia, and 3 with myelofibrosis. Among the eight patients showing transformation, two patients developing myelofibrosis derived from a group with normal cytogenetics, but the remaining six were categorized as showing de novo appearance of cytogenetic changes. Two leukemia patients had de novo cytogenetic changes at the time of leukemia diagnosis, whereas two patients with acute leukemia following myelofibrosis showed der(1;7) during their myelofibrosis period. Moreover, patients with der(1;7) did not receive any cytotoxic agents before the appearance of der(1;7), indicating that detection of der(1;7) may have predictive value for not only leukemic transformation but also unfavorable prognosis.

Spontaneous evolution of essential thrombocythaemia into acute megakaryoblastic leukaemia with trisomy 8, trisomy 21 and cutaneous involvement

Spontaneous transformation of essential thrombocythaemia (ET) into acute leukaemia is rare. We describe a case of ET that spontaneously transformed after 19 yrs uneventful follow-up into acute megakaryoblastic leukaemia. Cytogenetic analysis of bone marrow nucleated cells showed trisomy 8 and trisomy 21 at time of leukaemic transformation supporting the hypothesis that chromosomal abnormalities are part of the mechanism that drives the leukaemic progression independently of drug cytotoxicity. In addition, the very rare and intriguing finding of M7 FAB subtype evolution of ET was complicated by cutaneous involvement in the leukaemic process.

Long-term evaluation of 164 patients with essential thrombocythaemia treated with pipobroman: occurrence of leukaemic evolution

Essential thrombocythaemia (ET) is usually considered an indolent disease, but it may progress during its natural course into acute leukaemia (AL); however, an influence of myelosuppressive agents in the blastic transformation of ET cannot be excluded. We performed a retrospective study to assess the incidence of AL in ET patients treated with pipobroman (PB) as first-line therapy. One hundred and sixty-four patients with ET were managed with PB at a dose of 1 mg/kg/d until a stable platelet count below 400 x 10(9)/l was achieved. Maintenance therapy was given at a planned dose ranging between 0.2 and 1 mg/kg/d according to platelet count, in all cases, with a median daily dose of 25 mg (range 7-75 mg/d). The median treatment time was 100 months (range 25-243 months). The patients were evaluated for the occurrence of AL and/or secondary malignancies and survival end-points. AL was observed in nine patients (5.5%) after a median treatment time of 153 months (range 79-227 months). The overall survival (OS) and the event-free survival (EFS) at 120 months were 95% and 97%, whereas at 180 months, they were 84% and 76% respectively. In conclusion, this retrospective analysis shows a low incidence of AL in a large group of patients consecutively treated with PB as first-line chemotherapy. Therefore, an investigation of the role of myelosuppressive agents in the blastic transformation of ET would be of interest.

Acute Myeloid Leukemia and Myelodysplastic Syndromes Following Essential Thrombocythemia Treated With Hydroxyurea: High Proportion of Cases With 17p Deletion

Treatment with alkylating agents or radiophosphorous (32P) has been shown to carry a certain leukemogenic risk in myeloproliferative disorders (MPDs), including essential thrombocytemia (ET). The leukemogenic risk associated to treatment with hydroxyurea in ET, on the other hand, is generally considered to be relatively low. Between 1970 and 1991, we diagnosed ET in 357 patients, who were monitored until 1996. One or several therapeutic agents had been admistered to 326 patients, including hydroxyurea (HU) in 251 (as only treatment in 201), pipobroman in 43, busulfan in 41, and32P in 40. With a median follow-up duration of 98 months, 17 patients (4.5%) had progressed to acute myeloid leukemia (AML; six cases) or myelodysplastic syndrome (MDS; 11 cases). Fourteen of these patients had received HU, as sole treatment in seven cases, and preceded or followed by other treatment in seven cases, mainly pipobroman (five cases). The remaining three leukemic progressions occurred in patients treated with 32P (two cases) and busulfan (one case). The incidence of AML and MDS after treatment, using 32P alone and 32P with other agents, busulfan alone and with other agents, HU alone and with others agents, and pipobroman alone and with other agents was 7% and 9%, 3% and 17%, 3.5% and 14%, and 0% and 16%, respectively. Thirteen of 17 patients who progressed to AML or MDS had successful cytogenetic analysis. Seven of them had rearrangements of chromosome 17 (unbalanced translocation, partial or complete deletion, isochromosome 17q) that resulted in 17p deletion. They also had a typical form of dysgranulopoiesis combining pseudo Pelger Hüet hypolobulation and vacuoles in neutrophils, and p53 mutation, as previously described in AML and MDS with 17p deletion. Those seven patients had all received HU, as the only therapeutic agent in three, and followed by pipobroman in three. The three patients who had received no HU and progressed to AML or MDS had no 17p deletion. A review of the literature found cytogenetic analysis in 35 cases of AML and MDS occurring after ET, 11 of whom had been treated with HU alone. Five of 35 patients had rearrangements that resulted in 17p deletion. Four of them had been treated with HU alone. These results show that treatment with HU alone is associated with a leukemic risk of approximately 3.5%. A high proportion of AML and MDS occurring in ET treated with HU (alone or possibly followed by pipobroman) have morphologic, cytogenetic, and molecular characteristics of the 17p− syndrome. These findings suggest that widespread and prolonged use of HU in ET may have to be reconsidered in some situations, such as asymptomatic ET.

Acute Myeloid Leukemia and Myelodysplastic Syndromes Following Essential Thrombocythemia Treated With Hydroxyurea: High Proportion of Cases With 17p Deletion

Treatment with alkylating agents or radiophosphorous (32P) has been shown to carry a certain leukemogenic risk in myeloproliferative disorders (MPDs), including essential thrombocytemia (ET). The leukemogenic risk associated to treatment with hydroxyurea in ET, on the other hand, is generally considered to be relatively low. Between 1970 and 1991, we diagnosed ET in 357 patients, who were monitored until 1996. One or several therapeutic agents had been admistered to 326 patients, including hydroxyurea (HU) in 251 (as only treatment in 201), pipobroman in 43, busulfan in 41, and32P in 40. With a median follow-up duration of 98 months, 17 patients (4.5%) had progressed to acute myeloid leukemia (AML; six cases) or myelodysplastic syndrome (MDS; 11 cases). Fourteen of these patients had received HU, as sole treatment in seven cases, and preceded or followed by other treatment in seven cases, mainly pipobroman (five cases). The remaining three leukemic progressions occurred in patients treated with 32P (two cases) and busulfan (one case). The incidence of AML and MDS after treatment, using 32P alone and 32P with other agents, busulfan alone and with other agents, HU alone and with others agents, and pipobroman alone and with other agents was 7% and 9%, 3% and 17%, 3.5% and 14%, and 0% and 16%, respectively. Thirteen of 17 patients who progressed to AML or MDS had successful cytogenetic analysis. Seven of them had rearrangements of chromosome 17 (unbalanced translocation, partial or complete deletion, isochromosome 17q) that resulted in 17p deletion. They also had a typical form of dysgranulopoiesis combining pseudo Pelger Hüet hypolobulation and vacuoles in neutrophils, and p53 mutation, as previously described in AML and MDS with 17p deletion. Those seven patients had all received HU, as the only therapeutic agent in three, and followed by pipobroman in three. The three patients who had received no HU and progressed to AML or MDS had no 17p deletion. A review of the literature found cytogenetic analysis in 35 cases of AML and MDS occurring after ET, 11 of whom had been treated with HU alone. Five of 35 patients had rearrangements that resulted in 17p deletion. Four of them had been treated with HU alone. These results show that treatment with HU alone is associated with a leukemic risk of approximately 3.5%. A high proportion of AML and MDS occurring in ET treated with HU (alone or possibly followed by pipobroman) have morphologic, cytogenetic, and molecular characteristics of the 17p− syndrome. These findings suggest that widespread and prolonged use of HU in ET may have to be reconsidered in some situations, such as asymptomatic ET.

Thrombotic and hemorrhagic complications in chronic myeloproliferative disorders

Bleeding and thrombosis are major causes of morbidity and mortality in patients with chronic myeloproliferative disorders. We retrospectively evaluated 101 consecutive patients affected by primary thrombocytosis (46 male, 55 female, aged 18-84 years; mean +/- SD 61 +/- 15) followed for a period ranging from 6 months up to 10 years (median 5 years) at our hematological unit. At the time of diagnosis 48 patients were asymptomatic; 26 had clinical evidence of atherothrombosis (cerebral ischemic attacks, ischemic heart disease, peripheral occlusive arterial disease), ten had venous thrombosis, four experienced major hemorrhages, 23 presented microvascular ischemic manifestations namely erythromelalgia, paresthesias, acrocyanosis and dizziness. At presentation 51.2% of the patients had elevated serum lactic dehydrogenase, 34.5% hyperuricemia, and 23.4% serum creatinine > 1.2 mg/dL. Color Doppler ultrasound provided evidence of vascular stenosis or medium-intimal hyperplasia of epiaortic vessels in 48.9% of patients studied, and similar alterations of lower limb arteries in 23.8% of cases. Therapy modality included an antiplatelet agent (picotamide 300 mg/bid); a cytoreductive agent (busulphan, hydroxyurea, pipobroman or melphalan) was used when platelet count was > 800000/microL. Symptoms due to microvascular ischemia promptly regressed after picotamide and cytoreductive therapy. During follow-up. nine patients suffered from atherothrombotic events (transient ischemic attacks, ischemic stroke, unstable angina pectoris) and five developed deep vein thrombosis or superficial thrombophlebitis. Five patients experienced major hemorrhages (two melena, two hematuria, one perioperative bleeding); the two gastrointestinal hemorrhages occurred in patients self-medicated with non steroidal anti-inflammatory drugs, and the two episodes of hematuria occurred on oral anticoagulant therapy and aspirin respectively. No major bleeding occurred in patients on continuative therapy with picotamide, even in the presence of upper digestive tract disorders. Seven patients died: mortality resulted from one sudden coronary death, three solid neoplasia, one blast crisis, one anile, and one massive hemorrhage due to abdominal aortic prosthesis tearing. Our study suggests that a long-term antithrombotic prophylaxis with picotamide may be of benefit in patients affected by primary thrombocytosis; a controlled clinical trial is warranted to assess whether picotamide can ameliorate the natural history of the disease.

Central nervous system granulocytic sarcoma in a patient with essential thrombocythemia

We report a rare case of central nervous system granulocytic sarcoma (GS) in a patient with essential thrombocythemia (ET). The diagnosis of GS was established by morphological and cytochemical findings (peroxidase and naphthol-AS-D-chloroacetate esterase positivity) of neoplastic cells. GS was detected as an intracranial frontal mass 7 months before the transformation of ET in acute myeloid leukemia and relapsed as two extradural spinal masses during the course of leukemic evolution.