Juvenile Myelomonocytic Leukemia
Key Points for This Section
- Juvenile myelomonocytic leukemia is a childhood disease in which too many myelocytes and monocytes (immature white blood cells) are made in the bone marrow.
- Signs and symptoms of juvenile myelomonocytic leukemia include fever, weight loss, and feeling very tired.
- Certain factors affect prognosis (chance of recovery) and treatment options.
Juvenile myelomonocytic leukemia is a childhood disease in which too many myelocytes and monocytes (immature white blood cells) are made in the bone marrow.
Juvenile myelomonocytic leukemia (JMML) is a rare childhood cancer that occurs more often in children younger than 2 years. Children who have neurofibromatosis type 1 and males have an increased risk of juvenile myelomonocytic leukemia.
In JMML, the body tells too many blood stem cells to become two types of white blood cells called myelocytes and monocytes. Some of these blood stem cells never become mature white blood cells. These immature white blood cells are called blasts. Over time, the myelocytes, monocytes, and blasts crowd out the red blood cells and platelets in the bone marrow. When this happens, infection, anemia, or easy bleeding may occur.