Myelodysplastic Syndromes Flashcards
Myelodysplastic Syndromes (MDS) definition
stem cell disorders characterized by pancytopenia w/ maturation abnormalities
2 types of MDS
primary (de novo) - most of all idiopathic
secondary to therapy - chemo / radiation
Etiology of MDS
result from proliferation of abnormal cells - affects myeloid line mutation may be caused by chemical exposure, radiation or viral infection
Epidemiology of MDS
>50 yrs (median 70)
slight male predominance
Symptoms of MDS
asymptomatic
anemia symptoms
thrombocytopenia symptoms
neutropenia symptoms
Cellular Abnormalities of MDS
dysplasia including dyserythropoiesis, dysmyelopoiesis, dysmegakaryopoiesis
Dyserythropoiesis
defective development of RBCs
most common are oval macrocytes
MACRO, NORMO classification
Dysmyelopoiesis
abnormal granulation, hyposegmentation, possible left shift in the neutrophil line
Dysmegakaryopoiesis
giant platelets, abnormal platelet granulation small or abnormal megakaryocytes
Lab findings of MDS in PB
cytopenias & dysplasia (abnormal everything)
macro, normo anemia
oval macrocytes
RBC inclusions & NRBCs
Lab findings of MDS in BM
hypercellular!
all cell lines exhibit dysplasia
giant nucleated RBC precursors
ringed sideroblasts!
FAB classification of MDS
- Refractory Anemia (RA)
- Refractory anemia w/ ringed sideroblasts (RARS)
- Refractory anemia w/ excess blast (RAEB)
- Chronic myelomonocytic leukemia (CMML)
- Refractory anemia with excess blasts in transformation (RAEB-t)
Refactory Anemia (RA) - FAB
blasts in PB -<1%
blasts in BM- <5%
ringed sideroblasts - <15%
monos in BM - normal
RA with ringed sideroblasts (RARS) - FAB
blasts in PB- 1%
blasts in BM-<5%
ringed sideroblasts- 15%!!!
monos in BM - normal
RA with excess blasts (RAEB) - FAB
blasts in PB- <5%!!
blasts in BM - 5-20%!!!
ringed sideroblasts - variable
monos in BM - increased!!
RAEB in transformation (RAEB-t) - FAB
blasts in PB- >5%!!!!
blasts in BM - 21-30%!!!
ringed sideroblasts - variable
monos in BM - normal
Chronic Myelomonocytic leukemia (CMML) - FAB
blasts in PB- >5%
blasts in BM-<20%!
ringed sideroblasts- variable
monos in BM - normal
WHO classification of MDS
- RA
- RARS
- Refractory cytopenia w/ multilineage dysplasia (RCMD)
- RAEB (1 and 2)
- MDS associated w/ isolated del (5q syndrome)
- MDS, unclassified (MDS-U)
RA - WHO
PB- anemia, rare or no blasts
BM- Erythroid dysplasia only, <15% ringed sideroblasts
RARS - WHO
PB - anemia, rare or no blasts
BM - Erythroid dysplasia only, 15% ringed sideroblasts (!!)
RCMD - WHO
PB - cytopenias, rare or no blasts
BM - multilineage dysplasia, <15% ringed sideroblasts
RAEB 1 -WHO
PB - cytopenias, <5% blasts
BM - unilineage or multilineage dysplasia, 5-9% blasts!!
RAEB-2 WHO
PB- cytopenias, 5-19% blasts, AUER RODS PRESENT
BM- unilineage or multilineage dysplasia, 10-15% blasts!!!!, AUER RODS PRESENT
5q- syndrome WHO
PB - anemia, normal or INCREASED PLT, <5% blasts Isolated deletion of 5q cytogenetic abnormality
MDS - U WHO
PB- cytopenias, rare or no blasts
BM- unilineage dysplasia, <5% blasts
Variants of MDS
- hypoplastic MDS
- Therapy related MDS
- Childhood MDS
Hypoplastic MDS
the 10% of MDS cases that have hypocellular BM
difficult to distinguish from aplastic anemia
Therapy related MDS
MDS secondary to chemo/ radiation
highest incidence occurs 3-8 years after treatment
Childhood MDS
few cases have been reported
probably more but not correctly diagnosed
Cytogenetic Abnormalities that contribute to MDS
additional copy of chromosome 21
addition on chromosome 8
loss on chromosome 7
inversion on chromosome 3
del 5q
