Complications vascular complications thrombosis

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Complications vascular complications (thrombosis, hemorrhage) myeloid metaplasia acute leukemia Causes of Secondary Polycythemia spurious (decrease in plasma volume) poor tissue oxygenation high altitude cyanotic congenital heart disease or pulmonary disease hemoglobinopathies with increased O 2 affinity carbon monoxide poisoning local renal hypoxia renal artery stenosis renal cysts ectopic production of erythropoietin uterine leiomyoma cerebellar hemangioma hepatocellular cancer • pheochromocytoma renal cell cancer CHRONIC GRANULOCYTIC (MYELOGENOUS) LEUKEMIA (CML) overproduction of myeloid cells, erythoid cells and platelets in peripheral blood marked myeloid hyperplasia in bone marrow Clinical Features disorder of middle age 40% asymptomatic secondary to splenic involvement splenomegaly (most common physical finding) shoulder tip pain due to splenic infarction secondary to high blood histamine pruritus, peptic ulcer secondary to rapid cell turnover fever, weight loss secondary to anemia symptoms of anemia - most commonly fatigue secondary to gross elevation of the WBC (rare) • encephalopathy • priapism Diagnostic Features Philadelphia (Ph1) chromosome translocation between chromosomes 9 and 22 the c-abl proto-oncogene is translocated from chromosome 9 to “breakpoint cluster region” (bcr) of chromosome 22 to produce bcr-c-abl fusion gene, an active tyrosine kinase detection of this fusion gene is a diagnostic test for CML (present in over 90% of patients) leukocyte alkaline phosphatase (LAP) normal constituent of secondary neutrophil granules low or absent (normal or increased in other chronic myeloproliferative diseases and reactive states) peripheral blood film (see Colour Atlas H10) leukocytosis with early myeloid precursors eosinophils and basophils may be increased hypogranular basophils bone marrow myeloid hyperplasia with a left shift, increased megakaryocytes and increased reticulin or fibrosis Course/Outcomes chronic phase normal bone marrow function white blood cells differentiate and function normally accelerated phase • fever marked increase in basophils increased extramedullary hematopoiesis (unusual sites) transformation ––> disease similar to idiopathic myelofibrosis pancytopenia secondary to marrow aplasia
H28 – Hematology MCCQE 2002 Review Notes CHRONIC MYELOPROLIFERATIVE DISORDERS . . . CONT. acute phase (blast transformation) 2/3 develop a picture similar to AML • unresponsive to remission induction 1/3 develop a picture similar to ALL • remission induction (return to chronic phase) achievable • sepsis • bleeding • thrombosis Management symptomatic allopurinol and antihistamines chronic phase hydroxyurea or occasionally busulfan • interferon STI 571 only curative treatment is bone marrow transplantation IDIOPATHIC MYELOFIBROSIS (IMF) marrow replaced by fibrosis - abnormal megakaryocytes stimulate collagen deposition Clinical Features

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