Myelodysplastic Syndrome with Fibrosis
Definition
- Myelodysplastic syndrome with increased fibrosis
Diagnostic Criteria
- Not yet a separate WHO category, but:
- Clinically distinct (worse prognosis)
- Diagnostically distinct (special differential diagnostic problems)
- Diffuse coarse reticulin fibrosis with or without collagenization
- MF-2 or MF-3 in European consensus grading system (Thiele 2005)
- Any type of MDS may occur with increased marrow fibrosis
- Occurs in 15% of MDS patients
- Most common type is refractory anemia with increased blasts
- Usually results in an inadequate bone marrow smear
- Diagnosis may have to be based on the core
- CD34 staining may be valuable for identifying blasts in sections
- Usually associated with:
- Pancytopenia
- Dysplasia in at least two lineages
- Modest or absent splenomegaly
- Distinction between various MDS may be compromised by fibrosis but should be made, if possible, based on standard criteria:
Myelodysplastic Syndromes
| Circulating Blasts | Marrow Blasts | Ring Sideroblasts | Dysplastic Lineages | Cytopenias | |
|---|---|---|---|---|---|
| RCUD | <1% | <5% | <15% | Any 1 lineage | 1 or 2 |
| RARS | 0 | <5% | ≥15% | Only erythroid | 1 or 2 |
| RCMD | <1% | <5% | Variable | 2 or more lineages | 1, 2 or 3 |
| <5% | 5-9% | Variable | 1 or more | 1, 2 or 3 | |
| 5-19% | 10-19% or Auer rods | Variable | 1 or more | 1, 2 or 3 | |
| del(5q) | <1% | <5% | Variable | Frequently hypolobated small megakaryocytes | Usually 1 (anemia) |
- RCUD = refractory cytopenia (anemia, neutropenia or thrombocytopenia) with unilineage dysplasia; RARS = refractory anemia with ringed sideroblasts; RCMD = refractory cytopenia with multilineage dysplasia; RAEB = refractory anemia with excess blasts; del(5q) = 5q- syndrome
- All MDS must not have absolute monocytosis
- If present, consider chronic myelomonocytic leukemia
- If chemotherapy or radiation therapy related, should be reported as "therapy-related myeloid neoplasm"
- In children, consider provisional WHO entity "refractory cytopenia of childhood" for low blast count MDS
- Myelodysplastic syndrome unclassifiable (MDS-U)
- Must not meet criteria of any specific WHO category
- Persistent cytopenia(s) with any of the following:
- Unilineage marrow dysplasia with pancytopenia OR
- <1% blasts in blood, <5% blasts in marrow and cytogenetic abnormalities but no lineage with ≥10% dysplastic forms OR
- Findings of RCUD or RCMD but with 1% blasts in peripheral blood
- (2-4% blasts would be classified as RAEB-1)
- Nonclonal causes must be excluded
Dita Gratzinger MD PhD
Tracy I George MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting: 10/23/11
