Refractory Cytopenia with Multilineage Dysplasia (RCMD)
Supplemental Studies
- Cytogenetic abnormalities are found in about 50% of RCMD cases
- Other causes must be actively excluded clinically (see Differential Diagnosis at left)
Cytogenetic studies should be performed in all cases of myelodysplasia or suspected myelodysplasia
- FISH for MDS associated abnormalities is not indicated for screening but is helpful if <20 metaphases were examined on karyotyping
- In the setting of persistent cytopenia in the absence of definitive morphologic features of MDS:
- The following abnormalities are considered presumptive evidence of MDS
- Deletions
- -5, del(5q)
- -7, del(7q)
- del(9q)
- del(11q)
- del(12p)
- t(12p)
- -13, del(13q)
- i(17q), t(17p)
- idic(X)(q13)
- Translocations
- t(1;3)(p36.3;q21.2)
- t(2;11)(p21;q23)
- t(3;21)(q26.2;q22.1)
- inv(3)(q21q26.2) and t(6;9)(p23;q24)
- Most frequently present as AML and need to be closely monitored for overt transformation
- t(11;16)(q23;p13.3)
- The following are commonly found in MDS but are not by themselves considered definitional for MDS
Flow immunophenotyping
- Often shows decreased hematogones
- May show immunophenotypic abnormalities
- e.g. CD56 on blasts and monocytes
- Paroxysmal Nocturnal Hemoglobinuria clone may be present, particularly in RCUD
- CD55 and CD59 deficient RBC
Immunohistochemistry
- CD34+ blast clusters
- ≥3 clusters of ≥3 cells each
- Confers worse prognosis in MDS with <5% blasts
Bone marrow reticulin/trichrome stains
- Dense, diffuse fibrosis confers worse prognosis independent of IPSS
- Grade 2-3 per the European consensus scale (Thiele 2005)