Leukemias are cancerous malignant blood diseases, characterized by an abnormal proliferation of the cells found in bone marrow. There are different types of leukemias. Their common point is the proliferation of tissues responsible for the formation of white blood cells. They differ in particular by the nature of cells that multiply abnormally: acute leukemia
, in the case of cells that have not reached the end of their development, called blasts, chronic lymphocytic leukemia
when these cells are fully developed. There are also two other types of leukemia: chronic myeloid leukemia
, where the cells that are developing are mainly neutrophils, another type of mature white blood cell, and chronic myelomonocytic leukemia, where it is mature monocytes, yet another type of white blood cells, that proliferate. The characteristic of these two diseases is that the multiplication of cells may also affect other cells in the bone: they are then considered rather as myeloproliferative disorders.
Symptoms of leukemia will vary according to the category of leukemia in question. In general, the suggestive clinical signs of leukemia are:
- an increase in the size of the spleen, called splenomegaly;
- an increase in the size of lymph nodes, called adenomegaly;
- an increase in liver size.
Other signs depend on the more or less severe effect on the bone marrow and may be in the form of:
- signs of anemia with pallor and fatigue due to a decrease in red blood cells;
- signs of thrombocytopenia with bleeding due to a decrease in platelets;
- signs of infection with leukopenia.
The diagnosis is usually based on clinical signs, but abnormal cells may be discovered by chance in the blood.
Leukemias are suspected following blood tests studying different amounts of cells. Confirmations will possible follow an analysis of the bone marrow by aspiration, or with additional tests performed on blood samples, such as blood smears, immunophenotyping or certain molecular biology techniques.
As for the symptoms and the diagnostic confirmation, treatment will depend on the type of leukemia. In general, it is based on drug chemotherapy, treatment of potential complications during the course of the disease, and the attempt to inject hematopoietic stem cells or bone marrow cells taken from a healthy donor and implanted in the patient body.