Page 578 - TNFlipTest

H38 Hematology
Myeloid Malignancies
Toronto Notes 2019
Hematological Malignancies and Related Disorders
Leukemia
• ALL • CLL
Lymphoid Disorders
Lymphomas
• Hodgkin
• Non-Hodgkin
• B Cell
• T Cell
• Other cell origin
(e.g. NK)
Plasma Cell Dyscrasias
• Multiple myeloma • MGUS
• Waldenstrom’s
macroglobulinemia
Leukemia
• AML
Myeloid Disorders
MPNs
• PV • ET • CML • IMF
MDS
ALL = acute lymphocytic leukemia; AML = acute myeloid leukemia; CLL = chronic lymphocytic leukemia; CML = chronic myeloid leukemia; ET = essential thrombocythemia; IMF = idiopathic myelofibrosis; MDS = myelodysplastic syndromes; MGUS = monoclonal gammopathy of unknown significance; MPN = myeloproliferative neoplasms; PV = polycythemia vera
Figure 16. Overview of hematologic malignancies and related disorders
Myeloid Malignancies
Acute Myeloid Leukemia
Definition
• rapidlyprogressivemalignancycharacterizedbyfailureofmyeloidcellstodifferentiatebeyondblaststage
Epidemiology
• incidenceincreaseswithage;medianageofonsetis65yrold;80%ofacuteadultleukemias • accountsfor10-15%ofchildhoodleukemias
Risk Factors
• male,olderage,smoking,obesity,myelodysplasticsyndromes(MDS),benzene,radiation,Down Syndrome, alkylating agents and radiation therapy as treatment for previous malignancy
Pathophysiology
• etiologysubdividedinto:
■ primary: de novo
■ secondary: hematologic malignancies (e.g. myeloproliferative disorders and MDS) or previous
chemotherapeutic agents (e.g. alkylating agents) • uncontrolledgrowthofblastsinmarrowleadsto:
■ suppression of normal hematopoietic cells
■ appearance of blasts in peripheral blood – risk of leukostasis ■ accumulation of blasts in other sites (e.g. skin, gums)
■ metabolic consequences; tumour lysis syndrome
Clinical Features
• anemia,thrombocytopenia(associatedwithDICinpromyelocyticleukemia),neutropenia(evenwith normal WBC), leads to infections, and fever
• accumulationofblastcellsinmarrow
■ skeletal pain, andbony tenderness (especially sternum)
• organinfiltration
■ gingival hypertrophy (particularly myelomonocytic leukemia) – may present to dentist first ■ extramedullary involvement
■ hepatosplenomegaly (in ALL)
■ lymphadenopathy (not marked in ALL)
■ gonads (in ALL)
■ skin: leukemia cutis or myeloid sarcoma
■ eyes:hemorrhagesand/orwhitishplaques,Rothspots,cottonwoolspots,andvisionchanges
(uncommon)
• leukostasis/hyperleukocytosissyndrome(medicalemergency)
■ large numbers of blasts interfere with circulation and lead to hypoxia and hemorrhage – can cause diffuse pulmonary infiltrates, CNS bleeding, respiratory distress, altered mental status, and priapism
■ associated with AML more than ALL
• metaboliceffects;aggravatedbytreatment(rare)
■ increased uric acid → nephropathy, gout
■ release of phosphate → decreased Ca2+, decreased Mg2+
■ release of procoagulants → DIC (higher risk in acute promyelocytic leukemia)
• decreased or normal K+ before treatment, increased K+ after treatment (from lysed cells)
Investigations
• bloodwork
■ CBC: anemia, thrombocytopenia, variable WBC
■ INR, aPTT, fibrin degradation products (FDP), fibrinogen (in case of DIC)