Myeloid Neoplasms, Spleen and Thymus Flashcards
Acute Myeloid Leukemia (AML) has an increase in myeloblasts. Describe the steps necessary for this to occur.
- Mutations in hematopoietic stem cells
- Creation of a leukemic stem cell
- Proliferates and blocks differentiation
= accumulation of myeloblasts
What age group is at risk for Acute Myeloid Leukemia?
Can occur at ALL ages
Symptoms of Acute Myeloid Leukemia?
Fever
Fatigue
Bleeding/bruising
With Acute Myeloid Leukemia, where do the blasts accumulate?
BONE MARROW
What defines Acute Myeloid Leukemia?
Greater than 20% Blasts in the Bone Marrow
Greater than 20% blasts in the bone marrow?
AML (Acute Myeloid Leukemia)
Will there be blasts in the peripheral smear with AML?
NO - they are in the bone marrow
What is Aleukemic Leukemia?
No blasts in the peripheral smear
ex. AML
What 2 translocations can result in Acute Myeloid Leukemia?
t(8;21)
t(15;17)
t(8;21) or t(15;17)
Acute Myeloid Leukemia
Which translocation associated with AML involves younger patients with neutrophilic maturation?
t(8;21)
What product with the t(8;21) with AML blocks differentiation and causes an accumulation of blasts?
RUNX1 - RUNX1T1
- Blocks Core Binding Factor mediated differentiation and maturation
Which translocation associated with AML is known as Acute Promyelocytic Leukemia?
t(15;17)
What can be seen in cells with Acute Promyelocytic Leukemia (t(15;17) subtype of AML)?
Auer rods
Auer rods are seen with?
Acute Promyelocytic Leukemia
Normally, RAR binds ____ and initiates gene transcription for differentiation of myeloid cells
RA
With t(15;17) RAR is bound to ____ and cannot bind RA which means?
Bound to PML
==> NO differentiation; accumulation of blasts!
What is the treatment for t(15;17) in order for differentiation of the cells to occur?
Give All Trans RA
Those with t(15;17) are at a higher risk for?
Disseminated Intravascular Coagulation
What are 2 unusual presentations of Acute Myeloid Leukemia?
Gingival involvement
Soft tissue mass formation
CLONAL disorder with morphologic manifestations that can range through many cell lineages
Myelodysplastic Syndrome
What is considered a precursor to Acute Myeloid Leukemia?
Myelodysplastic Syndrome
Myelodysplastic Syndrome is considered a precursor to Acute Myeloid Leukemia. This is especially true if?
The Myelodysplastic Syndrome was caused by prior radiation therapy (t-MDS)
What do individuals present with, with Myelodysplastic Syndrome?
Cytopenias - low blood cells
3 classifications for Myelodysplastic Syndrome?
- Dysmorphic features in 1 or more lineages
- Chromosomal analysis
- Increase in BLASTS (but not to level of AML(20%))
What type of mutations cause Myelodysplastic Syndrome?
Driver mutations because it is a CLONAL disorder
RAEB 1
- seen with Myelodysplastic Syndrome
5%-9% increase in blasts
RAEB 2
- seen with Myelodysplastic Syndrome
10% - 19% increase in blasts
What does RAEB stand for?
Refractory Anemia with Excess Blasts
- Used with Myelodysplastic Syndrome
What drives proliferation with Myeloproliferative Neoplasms?
Constitutively active mutated Kinases
Describe the overall pathway of what can occur with Myeloproliferative Neoplasms
- Something in bone marrow proliferates
- Neoplastic stem cells travel to other sites
- Extramedullary Hematopoiesis occurs
= Fibrosis and Acute Leukemias occur
With Chronic Myeloid Leukemia it is a Myeloproliferative Neoplasm. What cell type proliferates?
Mature myeloid cells
What translocation is present with Chronic Myeloid Leukemia?
t(9;22) - BCR-ABL
t(9;22) causes a ______ to be constitutively active
Tyrosine kinase
What 4 things can classify Chronic Myeloid Leukemia?
Marked Leukocytosis (WBC >100K)
Increased Buffy coat
Splenomegaly
Extramedullary Hematopoiesis
What are the 3 phases of CML (Chronic Myeloid Leukemia)?
Chronic phase
Accelerated phase
Blast phase
Blasts increase towards what phase of Chronic Myeloid Leukemia?
Towards the Blast (last) phase
Myelofibrosis
Stroma proliferates
Polycythemia Vera
RBC proliferates
Essential Thrombocythemia
Platelets proliferate
What mutations are drivers for growth for myelofibrosis, polycythemia vera, essential thrombocythemia?
JAK2 Kinase mutations
Myelofibrosis affects what organ mostly?
Spleen
Clonal proliferations (neoplasms) of immature dendritic cells
Langerhans cell Histiocytosis
Langerhans cells are what type of cells?
Immature dendritic cells
What 2 things can be seen with Langerhans cell Histiocytosis?
- Grooved nuclei of langerhans cells
2. Tennis racket shaped Birbeck granules
Grooved nuclei of Langerhans cells and Birbeck granules classify?
Langerhans cell Histiocytosis
There may also be lots of _____ with Langerhans cell Histiocytosis
Eosinophils
What markers are used to identify Langerhans cell Histiocytosis?
S-100
CD1a
What causes reactive splenitis (splenomegaly)?
Viral infection
What causes congestive splenomegaly?
Hepatic dysfunction (bc of portal vein)
What is Hypersplenism (splenomegaly) associated with?
Cytopenias
What usually causes a splenic rupture?
Blunt trauma to abdomen
Splenic neoplasms are often involved with ______ malignancies
Hematologic
How easy is it for a splenic infarct to occur?
Very easy - blood only has 1 way into the spleen
Hyperplasia of the thymus and a Thymoma can both produce?
Autoantibodies
If Hyperplasia of the thymus or a Thymoma produce autoantibodies, what results?
Myasthenia gravis
Symptoms with Myasthenia Gravis
Muscle weakness that gets worse with activity