TN 53 (08-22)

DI 23022.463 Myelodysplastic Syndrome with Excess Blasts





Refractory anemia with excess blasts; RAEB; MDS with excess blasts; MDS-EB1; MDS-EB2


Myelodysplastic Syndrome with Excess Blasts (MDS-EB) is a rare type of myelodysplastic syndrome (MDS). In this MDS-EB, the number of very early forms of blood cells (blasts) are increased in the bone marrow and/or blood. There is also a low number of at least one type of blood cell. The early forms of cell types in the bone marrow (red blood cells, white blood cells, or platelets) may or may not look abnormal (dysplasia) under the microscope.

MDS-EB has a high likelihood of turning into acute myeloid leukemia (AML). It is classified into two types, based on how many of the cells in the bone marrow or blood are blasts:

  • MDS-EB1: Blasts make up 5% to 9% of the cells in the bone marrow, or 2% to 4% of the cells in the blood.

  • MDS-EB2: Blasts make up 10% to 19% of the cells in the bone marrow, or 5% to 19% of the cells in the blood; this type has a higher risk to become AML.

Some cases of MDS-EB are linked to known risk factors (such as smoking, chemotherapy, having a genetic syndrome that increases the chance of developing MDS). These factors lead to changes in the DNA in bone marrow cells which may cause MDS-EB to develop, but most often, the cause is unknown.

MDS affects males slightly more often than females. The disorder occurs in all age groups, but is far more common in older adults, occurring most often in individuals over 60 years of age. According to one estimate, 22 to 45 per 100,000 people over the age of 70 years have MDS. Approximately 20,000 new patients are diagnosed each year in the United States.


Diagnostic testing: The diagnosis of MDS-EB is made by:

  • A history and physical examination;

  • Complete blood count (CBC);

  • Examination of blood smear and bone marrow aspiration; and

  • Genetic testing.

Physical findings: Individuals with MDS-EB may present with:

  • Refractory anemia;

  • Constant fatigue;

  • Shortness of breath;

  • Pallor or unusual paleness;

  • Easy bruising and/or bleeding;

  • Petechiae or pinpoint-sized red spots beneath the skin;

  • Frequent infections;

  • Neutropenia (low white blood cell levels);

  • Thrombocytopenia (low platelet levels).

Other signs and symptoms of MDS-EB may include:

  • Firm cervical masses, which are highly suggestive of regional lymph node metastasis; or

  • Vocal fold paralysis, which implies involvement of the recurrent laryngeal nerve.

ICD-9: 238.73

ICD-10: D46.2; D46.9


Although the actual number varies within medical literature, most state that between 5-29 percent of cases of MDS-EB deteriorates into AML. The transition to leukemia is accompanied by worsening marrow function and the accumulation, first in the marrow and subsequently in the blood, of undeveloped immature cells called blasts which have no useful function and suppress any remaining marrow cell production. As a consequence, the complications from anemia, bleeding, and infection become life-threatening.

Survival for MDS-EB is short with median survival less than 2 years.


Treatment of MDS with excess blasts may include blood transfusions, supportive care, chemotherapy, radiotherapy, and bone marrow transplant.


Suggested MER for Evaluation:

  • Clinical history and examination that describes the diagnostic features of the impairment;

  • Complete blood count (CBC) results;

  • Biopsy; and

  • Genetic testing.

Suggested Listings for Evaluation:








13.06 A


* Adjudicators may, at their discretion, use the Medical Evidence of Record or the listings suggested evaluating the claim. However, the decision to allow or deny the claim rests with the adjudicator.

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DI 23022.463 - Myelodysplastic Syndrome with Excess Blasts - 08/10/2022
Batch run: 08/10/2022