--caused by clonal expansion of pluripotent stem cell in bone marrow (BM) causing abnormal production of erythroid, myeloid, andmegakaryocytic precursors
--reflected in PB smear and CBC results
--multiple BM cell lines usu affected, but one cell line may dominate
--TYPES:
1. Polycythemia Vera
2. Myelofibrosis
3. Essential Thrombocythemia
4. Chronic Myelogenous Leukemia (CML)
PCV = POLYCYTHEMIA VERA
--types:
----1. relative (dt decreased plasma volume, erythopoietin level normal)
----2. secondary (dt hypoxia from smoking, altitude, lung dz, EPO level increased)
----3. primary (malignant, ideopathic, EPO level low to none)
--increased HGB concentration and RBC mass
--increased blood volume and viscousity
--INCIDENCE: 1/1,000,000, 1.4 males: 1.0 females
--mean age at Dx: 60
--S/Sx: weakness, headache, light-headed, fatigue, dyspnea, bleeds easily (epitaxis)
--S/Sx: red face, engorged retinal veins, hepatomegaly, splenomegaly (75%), Raynaud's syndrome
--decreased O2 saturation in periphery
--Dx from LABS: suspect PCV if HCT > 52 in white male or > 47 in black or female, if HGB > 18 in white male or > 16 in female or black, or when simultaneous increase of RBC, WBC & PLT (panmyeolsis)
--LABS: common to see (but not diagnostic): increased uric acid, EPO (erythropoeitin low or undetectable, RBCs > 6 million
--RBC survival time decreases by 25%-->anemia and myelofibrosis may develop
--Bone Marrow: hypercellular
--immature WBC's and RBC's w/ anisocytosis, poikilocytosis: microcytes, elliptocytes and DACROCYTES in peripheral blood (PB)
--thrombocytosis w/ abn morph & if fx abn increased bleeding
--NEUTS with abnormal morphology
--panmyelosis = increased RBCs, WBCs, PLTs
MORE REPEATS??
--immature WBC’s, RBC’s with marked anisocytosis and poikilocytosis
--neutrophils with abnormal morphology may be seen (which abn?)
--thrombocytosis
--expanded blood volume & hyperviscosity-->tissue hypoxia, vessel thrombosis
--Splenomegaly in > 75% of patients
--RBC count > 6,000,000 /mm3
--O2 content of blood increased, but o2 sat decreased
--chronic-->increased cardiac output & increased capillary beds-->decrease tissue hypoxia
What shape is a dacrocyte?
TEARDROP SHAPE
MYELOFIBROSIS
--ideopathic condition in which bone marrow becomes fibrotic
--splenomegaly
--normo/normochromic anemia with DACROCYTES
--myeloid metaplasia: extramedullary hematopoiesis: cells formed in liver and spleen as they were during gestation
--peak incidence 50-70 years
--median survival 10 years from onset
--DX: BM biopsy shows fibrosis, dry aspiration common
--WBC and platelet counts high intially, lower as dz progresses
--LABS show: immature WBCs and RBCs, mild poikilocytosis, polychromatophilia and NRBCs, dacrocytes
--WBCs: initial leukocytosis wiht immature neuts
--may manifest secondary to PV (15-30% of cases), leukemia, lymphoma, multiple myeloma, TB, osteomyelitis, myelodysplastic syndrome MDS, BENZENE exposure, X-rays, gamma rays
THROMBOCYTHEMIA (Essential or primary)
--ideopathic platelet count above 500,000 in the absence of other myeloproliferative dz
--age 50-70
--markedly increased PLT
--BM megakaryocyte hyperplasia
--hemorrhagic or thrombotic tendency (new platelets don't work right)
--LABS: PLT 500,000-1,000,000, normal RBC mass, NO DACROCYTES, NO PHILADELPHIA XSOME (CML)
--CAUSES of SECONDARY (for DDX): acute infx, chronic inflam dz (RA, TB), IDA (iron deficiency anemia), hemolysis, cancer, lymphoma, splenectomy
CML = CHRONIC MYELOGENOUS LEUKEMIA: see LEUKEMIA post, just prior to this one