Myelodysplastic syndrome with single lineage dysplasia

ICD-O-2 Morphology

9980/1: Refractory anemia, NOS
9981/1: Refractory anemia without sideroblasts

ICD-O-3 Morphology

9980/3: Myelodysplastic syndrome with single lineage dysplasia
Effective 2001 and later


for cases diagnosed 2001 and later

Primary Site(s)

Primary site must be bone marrow (C421)

Abstractor Notes

Refractory anemia (RA) is a specific type of myelodysplastic syndrome that is characterized mainly by unilineage dysplasia affecting erythroid series. (Diagnosis of exclusion).

The principle sites of involvement are the peripheral blood and bone marrow.

There should be a period of observation of six months followed by a re-evaluation before a definitive diagnosis of RA is established.

For MDS diseases (9980, 9982, 9983, 9985, 9986, 9989, 9991, 9992, 9993), abstracting each of the subtypes would result in over-counting of the diseases.
1. Code only the first subtype that is diagnosed.
2. Do not change the histology code or create a new abstract for any subsequent specific MDS subtypes.

Diagnostic Confirmation

This is a histology for which the Definitive Diagnostic Method does not include Genetics Data or Immunophenotyping, thus Diagnostic Confirmation should never be 3. If genetics and/or immunophenotyping are available, re-review to see if a more specific neoplasm can be coded.


Not Applicable

Module Rule


Alternate Names

Aregenerative anemia
Myelodysplastic syndrome without ring sideroblasts and single lineage dysplasia
Refractory anemia, NOS
Refractory anemia without sideroblasts
Refractory cytopenia with unilineage dysplasia
Refractory neutropenia (2021+, for cases 2010-2020, see 9991/3)
Refractory thrombocytopenia ((2021+, for cases 2010-2020, see 9992/3)


RA is any of a group of anemic conditions not associated with another disease and is marked by a persistent, frequently advanced anemia that can only be successfully treated with blood transfusions. RA is only anemia.

The early cells that develop into red blood cells have an abnormal appearance (called dysplasia). The number of very early cells (called blasts) is normal (less than 5%).

The peripheral blood smear usually shows normochromic, normocytic, or normochromic macrocytic. Blasts are rarely seen and, if present, account for <1% of the white blood cells.

The erythroid precursors in the BM vary from decreased to markedly increased. The BM must show unequivocal evidence of dysplasia (dysplasia must be present in 10% or more erythroid precursors). Ring sideroblasts may be present. The BM biopsy is generally hypercellular.

Definitive Diagnostic Methods

Bone marrow biopsy
Clinical diagnosis

Genetics Data





Hematologic Transplant and/or Endocrine Procedures

Transformations from


Corresponding ICD-9 Codes

238.72 Low grade myelodysplastic syndrome lesions

Corresponding ICD-10 Codes

D46.0 Refractory anemia without sideroblasts, so stated
D46.4 Refractory anemia, unspecified

Corresponding ICD-10-CM Codes (U.S. only)

D46.0 Refractory anemia without ring sideroblasts, so stated (effective October 01, 2015)
D46.4 Refractory anemia, unspecified (effective October 01, 2015)

Signs and Symptoms

Easy bruising or bleeding
Petechiae (flat, pinpoint spots under the skin caused by bleeding)
Shortness of breath
Skin paler than usual
Weakness or feeling tired

Diagnostic Exams

Blood chemistry studies
Cytogenetic analysis
FISH (flourescence in situ hybridzation)
Flow cytometry
Peripheral blood smear

Progression and Transformation

1-2% of cases evolve to AML

Epidemiology and Mortality

Age: 65-70 years median age
Incidence: 10-20% of all MDS cases
Sex: no male or female predominance
Survival: 69-108 median survival time


Swerdlow SH, Campo E, Harris NL, Jaffe ES, Pileri SA, Stein H, Thiele J (Eds):
WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues (Revised 4th edition)
IARC: Lyon 2017
Section: Myelodysplastic syndromes
Pages: 106-109

International Classification of Diseases for Oncology, Third Edition, Second Revision. Geneva: World Health Organization, 2020.
Section: ICD-O-3.2 (2020) Morphological Codes

National Cancer Institute
Section: General Information About Myelodysplastic Syndromes