Unit 3: Myelodysplastic Disorders Flashcards
(72 cards)
Three Groups of Clonal Myeloproliferative Disorders:
- AMLs
- Chronic Myeloproliferative Disorders (CMPDs)
- Myelodysplastic Syndromes (MDSs)
MDSs are typically seen in what population?
in older (>50 years) pts., especially males
What are the 3 types of diseases of MDSs?
- Primary (de novo)
- Treatment-related (2-5 yrs. post-chemo.)
- Very rarely, inherited (FYI: There is a pedi. MDS in this category.
Myelodysplastic Syndromes (MDSs):
Often called preleukemias: they range from a mild anemia to a malignant disease that rapidly terminates in _____!
AML
Difficult disease to recognize for what it is. Incidence of MDS cases wasn’t even tracked until _____.
2001
MDS general characteristics:
Apparently the stem cell DNA sequences acquire permanent mutations, particularly involving chromosomes ___ and ____.
- Most cases involve a defect at the Myeloid Stem Cell
- Each mutated stem cell produces a unique clone w/ a specific cellular
defect….leading to multiple expressions!
5 and 7
MDS:
Apoptosis is _________ early in disease, but ___________ later when converting to leukemia
increased
decreased
MDS general characteristics:
Result is ineffective clonal _____________ ( = too few cells) plus morphologic
__________ (= “ugly” cells)!
hematopoiesis
dysplasia
- MDS cells apparently produce cytokines that kill off N. cells, so . .
- Progressive p.b. __________ occur, with dyspoiesis (abnormal development)
in 1 or more cell lines
cytopenias
All MDSs have…
______________– occurs first; see oval macrocytes (1 st thought? Megaloblastic anemia), megaloblastoid bone marrow with bizarre nRBCs, some ringed sideroblasts, & dimorphic RBCs
Dyserythropoiesis
Most MDSs have…
________________ - persistent basophilic cytoplasm, abnormal granules & nuclei, uneven cytoplasmic staining, & occ’l. Auer rods (even before it’s officially a leukemia).
Dysmyelopoiesis
Some MDSs have…
____________ - giant plts., bizarre & mononuclear megakaryocytes, & abnormal granules
Dysmegakaryopoiesis
What is a major feature of MDS?
what is NOT seen until disease transforms into leukemia?
*cytopenias
hyperproliferation
MDS can stay stable for years with only ________ evident.
dysplasia
Pts may be _________ to treatment once therapy is finally needed.
refractory
Do cells have normal function with MDS?
no, abnormal.
-these conditions have variable severity
MDS clinical symptoms
- Fatigue
- Fever
- Bleeding
-However, many pts. are asymptomatic in early stages.
General P.B. Findings in MDSs
- Progressive cytopenia
- Megaloblastoid dyserythropoiesis in bone marrow
- Neutropenia
- Giant plts., circulating micromegakaryocytes/-blasts! (Similar to AMegL)
Megaloblastoid dyserythropoiesis in bone marrow, which manifests in p.b. as…
Hgb <10 g/dL
Variable degrees of : aniso, poik, Howell-Jolly bodies, basophilic stippling, & bizarre nRBCs
MDS P.B findings with neutropenia?
↑ metas & myelos, with morphologic abnormalities; may be Auer rods, may exhibit pseudo-Pelger-Huet
General Bone Marrow Findings in MDSs?
- Bone marrow sample always required for diagnosis.
- Bone marrow generally always hypercellular due to
erythroid hyperplasia. - Ringed sideroblasts common.
General Bone Marrow Findings in MDSs:
Hallmark finding is…
***megaloblastoid dyserythropoiesis!!!
FAB Classification Scheme for MDSs relies on _____________ alone, so has limited prognostic utility.
morphology
-Each of these is pretty much a basic Refractory Anemia (RA), but with increasingly more severe problems overlaid on top of it
In order of increasing severity (some pts. will actually progress through each until it finally becomes an AML!):
- Refractory Anemia (RA)
- Refractory Anemia w/ringed sideroblasts (RARS)
- Refractory Anemia w/excess blasts (RAEB)
- Chronic Myelomonocytic Leukemia (CMML)
- Refractory Anemia w/Excess Blasts in Transformation (RAEBIT, or RAEB-t)
