Myelodysplastic syndrome, unclassifiable

Myelodysplastic syndrome, unclassifiable
ICD-O-3 Morphology
9989/3: Myelodysplastic syndrome, unclassifiable
Effective 2001 and later
for cases diagnosed 2001 and later
Primary Site(s)
Primary site must be bone marrow (C421)

Not Applicable
Module Rule
Alternate Names
Hypoplastic myelodysplastic syndrome (MDS)
MDS, unclassified
Preleukemia [OBS]
Preleukemic syndrome [OBS]
Smoldering leukemia
Blood: Cytopenias, no blasts
Bone marrow: <5% blasts, dysplasia in granulocytes or megakaryocytes

The myelodysplastic syndromes (MDS, formerly known as "preleukemia") are a diverse collection of hematological conditions united by ineffective production of blood cells and varying risks of transformation to acute myelogenous leukemia (AML). Anemia requiring chronic blood transfusion is frequently present.
Abstractor Notes
Myelodysplastic syndrome, NOS is a generic disease description. DCO cases or path report only cases may stay in this classification. In most cases, NOS histology is only the provisional diagnosis; the physician will run further diagnostic procedures and look for various clinical presentations to identify a more specific disease.

Further review of the medical record should be done to look for the tests listed as definitive diagnosis. The more specific myelodysplastic syndromes are:
1. Refractory anemia (9980/3)
2. Refractory neutropenia (9991/3)
3. Refractory thrombocytopenia (9992/3)
4. Refractory anemia with ring sideroblasts (9982/3)
5. Refractory cytopenia with multilineage dysplasia (9985/3)
6. Refractory anemia with excess blasts (9983/3)
7. Refractory cytopenia of childhood (9985/3)

If the characteristics of a specific subtype of MDS develops later in the course of the disease, change the histology code to the more specific diagnosis.
The peripheral blood and bone marrow are the principal sites of involvement.

About 10% of MDS patients have bone marrow that is hypocellular. These cases are referred to as hypoplastic MDS. When considering the diagnosis of hypoplastic MDS, it is important to exclude toxic myelopathy and auto-immune disorders.

This is a clinical diagnosis. When the testing has excluded other diseases, the physician uses the information from the equivocal test results plus the patient's clinical history to make a diagnosis of myelodysplastic syndrome.

The patient receives supportive care. Red blood cells are transfused for anemia.
Definitive Diagnostic Methods
Bone marrow biopsy
Clinical diagnosis
Genetics Data
Bone marrow transplant
Stem cell transplant
Transformations from
Corresponding ICD-9 Codes
238.75 Myelodysplastic syndrome, unspecified
Corresponding ICD-10 Codes
D46.9 Myelodysplastic syndrome, unspecified
Corresponding ICD-10-CM Codes (U.S. only)
D46.9 Myelodysplastic syndrome, 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
Progression and Transformation
Epidemiology and Mortality