Chronic myelomonocytic leukemia (CMML) is a condition in which the body creates an excessive number of immature white blood cells, known as myeloblasts and myelocytes. These cells impede the formation of monocytes, which both fight infection and help other blood cells in the body to implement immunity. The extra cells also cause havoc in the body by taking up space needed in the bone marrow for platelets and red blood cells. As a result, a patient can suffer several problems including anemia, infection, or the tendency to bleed easily.
The condition is most common among older males. It is most commonly caused by environmental elements, chemicals, and exposure to radiation. Some cases of chronic myelomonocytic leukemia are also attributed to the use of some kinds of anticancer medications. The severity of the condition depends on the number of immature while blood cells, or blasts, in the bone marrow or blood; chromosomal changes; how many platelets or white blood cells are in the bone marrow and blood; and whether the patient has anemia.
There are two primary types of chronic myelomonocytic leukemia, which are distinguished by what percentage of blasts are in the bone marrow and blood, type CMML-1 and CMML-2. Type CMML-1 indicates there are less than 10 percent blasts present in the bone marrow and five percent that exist in the blood. The CMML-2 type typically has a range of 10 to 19 percent bone marrow blasts and five to 19 percent blood blasts.
Symptoms of chronic myelomonocytic leukemia include anemia, a sensation of fullness under the ribs, and an enlarged spleen or liver. Some patients may get leucopenia, an infection caused by a low white blood cell count. Other signs of CMML include bruising and bleeding caused by insufficient counts of platelets and pinpoints of blood coming from the skin known as petechiae.
Chronic myelomonocytic leukemia is usually not curable. It can be treated with drugs such as cytarbine, decitabine, and imatinib, depending on the nature of the condition. If an adequate donor can be found, a stem cell transplant can sometimes cure CMML, particularly in juvenile patients.
The average patient who is diagnosed with chronic myelomonocytic leukemia is expected to live from one to two years after treatment commences. Some factors work against patient survival rate, including a large spleen, severe anemia, and a high lactate dehydrogenase (LDH) level. Survival is also less likely for patients who have a high number of blasts or who have an abnormally high count of white blood cells overall. In some patients who are not cured, CMML could turn into acute myelogenous leukemia (AML).
