Stages of Hairy Cell Leukemia

There is no standard staging system for hairy cell leukemia.

Staging is the process used to find out how far the cancer has spread. Groups are used in place of stages for hairy cell leukemia. The disease is grouped as untreated, progressive, or refractory.

Untreated hairy cell leukemia

The hairy cell leukemia is newly diagnosed and has not been treated except to relieve symptoms such as weight loss and infections. In untreated hairy cell leukemia, some or all of the following conditions occur:

• Hairy (leukemia) cells are found in the blood and bone marrow.
• The number of red blood cells, white blood cells, or platelets may be lower than normal.
• The spleen may be larger than normal.

Progressive hairy cell leukemia

In progressivehairy cell leukemia, the leukemia has been treated with either chemotherapy or splenectomy (removal of the spleen) and one or both of the following conditions occur:

• There is an increase in the number of hairy cells in the blood or bone marrow.
• The number of red blood cells, white blood cells, or platelets in the blood is lower than normal.

There are three ways that cancer spreads in the body.

When cancer cells spread outside the blood, a solid tumor may form. This process is called metastasis. The three ways that cancer cells spread in the body are:

• Through the blood. Cancer cells travel through the blood, invade solid tissues in the body, such as the brain or heart, and form a solid tumor.
• Through the lymph system. Cancer cells invade the lymph system, travel through the lymph vessels, and form a solid tumor in other parts of the body.
• Through solid tissue. Cancer cells that have formed a solid tumor spread to tissues in the surrounding area.

The new (metastatic) tumor is the same type of cancer as the primary cancer. For example, if leukemia cells spread to the brain, the cancer cells in the brain are actually leukemia cells. The disease is metastatic leukemia, not brain cancer.