Other Names: Myelodysplastic/myeloproliferative neoplasm

Myelodysplastic/myeloproliferative diseases are a group of diseases of the blood and bone marrow in which the bone marrow makes too many white blood cells. These diseases have features of both myelodysplastic syndromes and myeloproliferative disorders. In myelodysplastic diseases, the blood stem cells do not mature into healthy red blood cells, white blood cells, or platelets and as a result, there are fewer of these healthy cells. In myeloproliferative diseases, a greater than normal number of blood stem cells develop into one or more types of blood cells and the total number of blood cells slowly increases. The 3 main types of myelodysplastic/myeloproliferative diseases include chronic myelomonocytic leukemia (CMML); juvenile myelomonocytic leukemia (JMML); and atypical chronic myelogenous leukemia (aCML). When a myelodysplastic/myeloproliferative disease does not match any of these types, it is called myelodysplastic/myeloproliferative neoplasm, unclassifiable (MDS/MPN-UC). 


Pathophysiology and Epidemiology

In most cases, the cause of myelodysplastic/myeloproliferative disease is unknown, and there is limited information regarding potential causes. No specific genetic defects have been identified for any of the diseases. The specific cause of chronic myelomonocytic leukemia (CMML) is unknown, but exposure to occupational and environmental carcinogens, ionizing radiation, and cytotoxic agents have been associated in some cases. The cause of juvenile myelomonocytic leukemia (JMML) is not known; however, children with neurofibromatosis type 1 (NF1) are at increased risk for developing JMML, and up to 14% of cases of JMML occur in children with NF1. Atypical chronic myelogenous leukemia (aCML) has been associated with cytogenetic abnormalities in as many as 80% of individuals with the disease; however, no cytogenetic abnormality is specific. Myelodysplastic/myeloproliferative neoplasm, unclassifiable (MDS/ MPN-UC) (also known as mixed myeloproliferative/ myelodysplastic syndrome) also has no known cause.


Signs and Symptoms

The most common symptoms of CMML and JMML include:

  • Fever
  • Fatigue
  • Weight loss

The most common symptoms of aCML include:

  • Easy bruising or bleeding
  • Fatigue 


Management and Treatment

FDA approved treatments for multiple myeloma include:


Clinical Trials

For a full list of clinical trials relating to myelodysplastic/myeloproliferative diseases, go here.

Mikkael Sekeres, MD: Combination Therapy Shows Promise in Rare Forms of Leukemia, including MDS

Jennifer Elliott, PhD: Promising Phase 2 Trial Results For Patients With Myelodysplastic Syndrome and AML



Aplastic Anemia and MDS International Foundation

Leukemia and Lymphoma Society 

American Cancer Society



To learn more about rare cancers, visit our Rare Cancers page