85 Primary Myelofibrosis Flashcards
TRUE OR FALSE
The the fibrosis in PMF is secondary, not primary
TRUE
The the fibrosis in PMF is secondary, not primary
The only cancer in the medical lexicon not so designated; rather, it is named for an epiphenomenon in the extracellular matrix
PMF
Central pathologic change in PMF
Neoplastic (dysmorphic) megakaryocytopoiesis
Mutations in PMF
50% JAK2 gene
25% Calreticulin (CALR) gene
~5%Thrombopoietin receptor (C-MPL) gene
Percentage of triple-negative PMF
10%
In infants, the disorder can mimic the classic disease or show certain features but not others, such as ________________
Absence of hepatosplenomegaly
TRUE OR FALSE
In young and middle-age adults, PMF is similar to that in older subjects, although the proportion of indolent cases may be higher, and the disease occurs in boys twice as frequently as in girls.
FALSE
In young and middle-age adults, PMF is similar to that in older subjects, although the proportion of indolent cases may be higher, and the disease occurs in girls twice as frequently as in boys.
TRUE OR FALSE
In adults, the disease occurs with about equal frequency in men as in women.
TRUE
In adults, the disease occurs with about equal frequency in men as in women.
Exposure to high concentrations of __________ or __________________ preceded the development of PMF in a very small number of cases in the past.
Benzene
Very-high-dose ionizing radiation
Benzene in exposures greater than __________ is associated with an increased relative risk of acute myelogenous leukemia (AML) but not of chronic myelogenous leukemias.
40–200 ppm-years
TRUE OR FALSE
Most lymphocytes, and especially most long-lived T-lymphocytes are formed before acquired JAK2 V617F mutational event and are thus not part of PMF clone.
TRUE
Most lymphocytes, and especially most long-lived T-lymphocytes are formed before acquired JAK2 V617F mutational event and are thus not part of PMF clone.
JAK2 gene mutation in exon 12 account for _____ of PMF
~1%
JAK2 V617F is a dominant, gain-of-function mutation in the gene residing on chromosome _________
Chromosome 9p24
Percentage of JAK2 Mutation in:
PV:
PMF:
ET:
Percentage of JAK2 Mutation in:
PV: 98%
PMF: 60%
ET: 55%
Absent in most healthy individuals
A negative regulator of three important pathways in hematopoiesis—JAK2/STAT5, AKT, and MAPK—as well as in inflammation
LNK protein
Non-Driver Somatic Mutations that predict an inferior prognosis
ASXL1/SRSF2
Non-Driver Somatic Mutations associated with progression to AML from an MPN
RUNX1, TP53, NRAS, WT1, FLT3, IDH1/2, and TET2
High levels of fibroblastic factors __________________ resulted in intense fibrosis in animal models.
TGF-β 1 and platelet-derived growth factor [PDGF]
Increased ______________ was thought to be the principal cause of osteosclerosis
Osteoprotegerin
In PMF, it is the most prominent alteration in this clonal myeloid disease and is responsible for most of its major manifestations
Neoplastic megakaryopoiesis
Constitutive mobilization and circulation of CD34+ cells are prominent features of the clonal expansion.
TRUE OR FALSE
Microvessel density and marrow blood flow are increased in patients with PMF.
TRUE
Microvessel density and marrow blood flow are increased in patients with PMF.
Causes of anemia in PMF
- Decreased erythropoiesis
- Shortened red cell survival
- Effects of splenomegaly on the distribution of red cells in the circulation
- Hemolysis
Synonym for PMF
Megakaryocytic myelosis
Chronic megakaryocytic leukemia
Four of the five major types of collagen are present in normal marrow:
- Type I in bone
- Type III in blood vessels
- Types IV and V in basement membranes
The fine reticulin fibers that appear after silver impregnation of marrow are principally _________ collagen
Type III collagen
They do not stain with trichrome dyes
The thicker collagen fibers are principally ____________ collagen and stain with trichrome dyes, but do not impregnate with silver.
Type I collagen
Collagen types I, III, IV, and V are increased in PMF , but _______________ is increased uniformly and preferentially.
Type III collagen
In terms of fibroplasia, all are increase except for
Collagenase
Plasma level of matrix metalloprotein III
Marrow fibrosis in PMF is most closely correlated with _____________________.
Increased neoplastic and dysmorphic megakaryocytes in the marrow
TRUE OR FALSE
The increased pathologic emperipolesis (the entry of neutrophils and other marrow cells into the canalicular system of megakaryocytes), evident in human PMF and in mouse models, suggests this may be an additional mechanism of α-granule injury and release of TGF-β and PDGF.
TRUE
The increased pathologic emperipolesis (the entry of neutrophils and other marrow cells into the canalicular system of megakaryocytes), evident in human PMF and in mouse models, suggests this may be an additional mechanism of α-granule injury and release of TGF-β and PDGF.
TRUE OR FALSE
The fibroblastic proliferation in marrow is not an intrinsic part of the abnormal clonal expansion of hematopoiesis.
TRUE
The fibroblastic proliferation in marrow is not an intrinsic part of the abnormal clonal expansion of hematopoiesis.
Extramedullary hemopoiesis is almost always present in what organs
Liver and spleen
Pathophysiology of extramedullary hematopoiesis
Escape of progenitor cells from marrow and their lodgment in other organs
TRUE OR FALSE
Reversion of the liver and spleen to their fetal hematopoietic functions (metaplasia) is a major factor in extramedullary hematopoiesis, and quantitatively significant, effective hematopoiesis occur outside of the marrow
FALSE
Reversion of the liver and spleen to their fetal hematopoietic functions (metaplasia) is NOT a MAJOR factor in extramedullary hematopoiesis, and quantitatively significant, effective hematopoiesis DOES NOT occur outside of the marrow
The most frequent self-reported complaint and is disproportionate to the degree of anemia.
Fatigue
Severe left upper quadrant or left shoulder pain can occur from __________________
Splenic infarction and perisplenitis
Occasionally, bone pain is prominent, especially in the ________________.
Long bones of the lower extremities
Fatigue, weight loss, cachexia, night sweats, and bone pain are more frequent later in the course of the disease and are related to the ______________________ that are a key feature of the disease
Increase in circulating inflammatory cytokines
TRUE OR FALSE
Splenomegaly is present on palpation or imaging studies in some of patients at the time of diagnosis, and hepatomegaly is detectable in two-thirds of patients.
FALSE
Splenomegaly is present on palpation or imaging studies in almost ALL patients at the time of diagnosis, and hepatomegaly is detectable in TWO-THIRDS of patients.
Proportion of splenomegaly
Mildly:
Moderately enlarged:
Massive:
Mildly: one-fourth
Moderate: half
Massive: one-fourth
A syndrome that closely mimics the raised and tender plaques of Sweet syndrome
Neutrophilic dermatosis
- The dermatopathology of neutrophilic dermatosis is different from leukemia cutis and is unrelated to infection or vasculitis.
- The predominant histologic lesion is an intense polymorphonuclear neutrophilic infiltrate.
These cutaneous lesions in PMF may have myeloid cells with giant cells carrying ________ markers characteristic of megakaryocytes
CD61
Percentage of patient with Prefibrotic Primary Myelofibrosis
Without overt reticulin fibrosis in the marrow
25%
Constant finding in prefibrotIc PMF
Thrombocytosis
The most important distinction or prefibrotIc PMF with ET
In PMF, bizarre changes are evident with wide variation in megakaryocyte size, from very small to giant size cells.
Nuclear lobulation is abnormal, with bulky multilobulation, hypolobulation, and free megakaryocyte nuclei in the marrow spaces.
In ET, megakaryocytes are increased, but they do not display the dysmorphia observed in PMF.
Symptoms or signs leading to diagnosis of Extramedullary (Fibrohematopoietic) Tumors
(1) identification of a mass on imaging regardless of location
(2) appearance of signs or symptoms of an effusion in the thorax or abdomen
(3) unexpected neurologic signs
(4) another finding that appears unexpected in a patient with PMF
TRUE OR FALSE
Portal vein thrombosis is a complication of PMF and occasionally precedes disease onset.
TRUE
Portal vein thrombosis is a complication of PMF and occasionally precedes disease onset.
TRUE OR FALSE
Abnormalities of humoral immune mechanisms have been observed in as much as half of patients with PMF.
TRUE
Abnormalities of humoral immune mechanisms have been observed in as much as half of patients with PMF.
Causes of nonclonal secondary myelofibrosis
Lupus erythematosus, Vasculitis, polyarteritis nodosa, ulcerative colitis, scleroderma, biliary cirrhosis, Sjögren syndrome, and acute reversible myelofibrosis responsive to glucocorticoids
Imaging that can uncover evidence of new bone formation and periosteal thickening (osteosclerosis)
MRI
Imaging that provide evidence for increased bone formation, bone thickening, and higher proportions of cancellous and of woven bone.
Lumbar spine dualenergy x-ray absorption studies and quantitative computed tomography
Approximately _____ of patients with PMF will experience a significant thrombotic event during the ___________ of the disease.
10%
First four years
The two principal risk factors for thrombosis are :
Elevated leukocyte count and age
Not platelet count
The combination of the JAK2 mutation, leukocytosis, and age predicted the highest incidence of thrombosis.