Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (CLL/SLL)

Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (CLL/SLL) is a type of cancer that affects the blood and lymphatic system, specifically involving a type of white blood cell called B lymphocytes. It usually progresses slowly and often affects older adults. The disease causes an abnormal buildup of these lymphocytes in the blood, bone marrow, lymph nodes, and other organs. This buildup can lead to symptoms like swollen lymph nodes, fatigue, and increased risk of infections. Because it affects the immune system, people with CLL/SLL may have trouble fighting off infections and may experience anemia or bleeding problems.

Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (CLL/SLL) is a mature B-cell neoplasm characterized by the clonal proliferation and accumulation of small, mature-appearing lymphocytes in the peripheral blood, bone marrow, lymph nodes, and spleen. It arises from a malignant transformation of B cells, often due to genetic abnormalities such as deletions in 13q14 or mutations in TP53. The disease is the most common adult leukemia in Western countries and typically presents with lymphocytosis, lymphadenopathy, and splenomegaly. The malignant B cells express CD5, CD19, CD20 (dim), and CD23, which helps distinguish CLL/SLL from other lymphoproliferative disorders. The clinical course is variable, ranging from indolent to aggressive forms, and it can lead to immunodeficiency and marrow failure. The distinction between CLL and SLL is based on the primary site of involvement: blood and marrow for CLL, lymph nodes for SLL.