C91: Lymphoid leukaemia

C91.1: Chronic lymphocytic leukaemia of B-cell type

Chronic lymphocytic leukaemia of B-cell type is a type of cancer that starts from cells that become certain white blood cells (called B-cells) in the bone marrow. The cancer (leukemia) cells start in the bone marrow but then go into the blood. It's called 'chronic' because it progresses more slowly than other types of leukemia. The particular type of leukemia described here affects B cells, which are immune cells that create antibodies to fight off infections. Over time, these cancerous B cells multiply and crowd out healthy blood cells leading to a shortage of red cells (causing anemia), platelets (leading to increased bleeding and bruising) and healthy white cells (leading to infections). Symptoms may include fatigue, weight loss, frequent infections, and swollen lymph nodes. It generally affects older adults and is rarely seen in individuals under the age of 40.