Chronic lymphocytic leukemia (CLL) is a cancer in which the bone marrow (the soft, spongy center of bones) produces too many lymphocytes, a type of white blood cell. 

Chronic Lymphocytic Leukemia Overview and Diagnosis

Chronic lymphocytic leukemia is similar to acute lymphoblastic leukemia (ALL), except that in ALL the disease progresses quickly (within weeks or a few month; with CLL, the disease progresses very slowly, usually over the course of years. Also, with chronic lymphocytic leukemia, the abnormal cells affected are partially mature; with ALL, they are completely immature. These abnormal leukemia cells survive longer than normal cells and start to crowd out the normal cells. Chronic lymphocytic leukemia differs from chronic myeloid leukemia in that it affects a different type of white blood cell. Chronic lymphocytic leukemia is the most common leukemia in adults. The average age at diagnosis is 71, and CLL is rare in people under age 40. The 5-year survival rate for CLL is 83%.

CLL diagnosis generally includes:

  • a physical exam
  • blood tests and evaluation
  • radiology imaging for the evaluation and staging of your leukemia, such as aPET/CT scan. The PET/CT hybrid scanner is a state-of-the-art diagnostic imaging system that provides more precise information and localization for many cancers; and does it quicker than conventional PET imaging.
  • biopsy — either a bone marrow biopsy to examine blood cells, or a surgical orCT-guided biopsyto obtain lymph node tissue samples. Usually biopsy procedures are not carried out at the initial visit, but arranged for a later date, once we have gathered your other information and imaging.

Leukemia Multidisciplinary Conference

At BIDMC, we review all of your information with the full blood cancer treatment team in our weekly multidisciplinary conferences. Our radiologists report on your imaging studies and our hematopathologists (pathologists who specialize in blood diseases) review the results of your biopsy. Hematologists, oncologists and radiation oncologists voice their opinions. Together as a team focused solely on you, we reach agreement on the best treatment options for your particular situation.


The specific chronic lymphocytic leukemia treatment you receive will depend on the sub-type of CLL you have, how far it has progressed when CLL treatment starts, how the CLL responds to initial treatment, and other factors. It may include:

  • Chemotherapy – the use of chemicals, through one or more types of medication, to treat disease. Chemotherapy interferes with cancer cells’ ability to grow. It can be administered intravenously (through an IV), subcutaneously (an injection below the skin), or orally (as a pill to swallow)
  • Targeted therapy – the use of medications to target the specific gene mutations present in your chronic lymphocytic leukemia
  • Stem cell transplant – also called bone marrow transplant, in this procedure a donor's stem cells are transfused into your blood. The transplanted stem cells go from your blood to your bone marrow. Through this process, the cells that produced the abnormal cells are replaced with healthy cells that produce normal blood cells.

Types of bone marrow/stem cell transplants:
  • Autologous stem cell transplants , which are stem cells that come from your own bone marrow or blood. Doctors extract stem cells from your blood or bone marrow, place them in frozen storage, and re-infuse them back into your body following high-dose chemotherapy to eliminate blood cancers.
  • Allogeneic stem cell and bone marrow transplants , which are stem cells that come from matched related donors (siblings, for example), or from matched unrelated donors or donated umbilical cords. As a recognized site of the National Marrow Donor Program, BIDMC has access to an international registry of more than 5 million possible unrelated donors.
Dedicated Stem Cell Lab

Our stem cell/immunotherapy laboratory is a key component of our bone marrow transplantation service. The stem cell lab:

  • Excels in the special and meticulous handling of human cells
  • Provides expertise in the collection, storage, and manipulation of bone marrow and stem cell products so they are ready to be transplanted (re-infused) into the patient

Learn More

Our world-renown hematologists, oncologists, radiation oncologists, radiologists and hematopathologists provide state-of-the-art diagnosis and management for blood cancers, including CLL.

Hematologic Malignancies/Bone Marrow Transplant (BMT) Program