Chronic neutrophilic leukemia (CNL): Overview
- Chronic neutrophilic leukemia (CNL) is a very rare type of blood cancer in which your bone marrow makes a lot of neutrophils
- CNL is more commonly seen in older adults
- CNL can evolve into acute leukemia, the most aggressive type of blood cancer
- The treatment for CNL can vary, depending on your symptoms, personal characteristics, and how fast it is likely grow or spread
What is chronic neutrophilic leukemia (CNL)?
Dr. Ghaith Abu-Zeinah, MD, from New York-Presbyterian Hospital of Weill Cornell Medicine (WCM) discussed that "CNL primarily affects the neutrophil count or the white blood cell count and particularly neutrophil cell lineage."CNL is a type of cancer that falls under the category of myeloproliferative neoplasms (MPNs). MPNs consist of a variety of bone marrow disorders in which the bone marrow makes an excessive amount of blood cells. Bone marrow is the spongy tissue inside large bones where white blood cells, red blood cells, and platelets are made from specialized stem cells. There are five types of white blood cells in your body: neutrophils, lymphocytes, monocytes, eosinophils, and basophils. Neutrophils are the most abundant type of white blood cell, and they protect our body's immune system. Think of your immune system as the chief of your body's defense unit that sends the neutrophils as first responders to infection. It may be normal for your body to produce more neutrophils in certain cases such as infection, inflammation, or reaction to medications. If your bone marrow makes an abnormally large number of neutrophils, this can lead to a condition called CNL. Your doctor will check your blood to exclude other conditions before reaching the confirmed diagnosis of CNL.What Increases Your Risk for CNL?
- While experts don't know exactly what causes CNL, they do point to certain mutations in our body. CNL is related to a mutation in a CSF3R protein that promotes the production of neutrophils.
- Having a family history of CNL can also increase the risk.
What are the symptoms of chronic neutrophilic leukemia (CNL)?
It is always good to know what symptoms to look for when you’re concerned about CNL. In the early stage, you may not have any symptoms for a long period of time; a routine blood test at your doctor's office may show an abnormally higher number of neutrophils. Later in the course of the disease, you may feel a dull pain in the belly as your spleen grows, have night sweats, or feel more tired than usual. Increasing symptoms can sometimes be an ominous sign of the disease becoming more aggressive.
Read More Symptoms of CNL may include
- stomach problems, such as pain in the upper belly due to a big spleen can be a benchmark to determine your condition
- frequent headaches
- Sweat a lot, particularly at night
- painful, swollen joints, especially in the big toe, ankle, or knee, commonly known as gout
- Unexpected bleeding is most commonly nosebleed, bleeding from gum or mouth, or blood in the stool.
- Feeling weak or more dizzy than usual
- itching, especially after a warm bath or shower
How chronic neutrophilic leukemia (CNL) is diagnosed?
Most of the time CNL is diagnosed by a physician performing a routine blood test. Your doctor will come to a diagnosis based on the following tests:- Complete blood count (CBC): to look for hemoglobin, different types of white blood cells, and platelet. In CNL, your white blood cell count is higher than normal and the majority are neutrophils.
- The blood smear is to examine your blood samples under a microscope to rule out other types of blood cancer such as acute leukemia.
- Bone marrow examination: A bone marrow biopsy may be needed to confirm the diagnosis. Your doctor takes a small sample of your bone marrow, usually from the hip bone. Then the pathologist looks at the cells under a microscope to determine how many neutrophils your body has, the presence of mutation, and/or chromosomal abnormality on the cancer cells.
What Treatment Will Work Best Against Your Chronic Neutrophilic Leukemia (CNL)?
Once a confirmed diagnosis of CNL is made, your doctor can focus on the next important step- how to treat you. Given that CNL is a very type of cancer, treatment options are unfortunately limited. If you have indolent cancer and you don't have any bothersome symptoms, you may not need the treatment right away. Your doctor may take the following steps to manage your symptoms and prevent any future complications.- Medicines such as hydroxyurea can be given by the doctor to keep your bone marrow from making too many neutrophils. Hydroxyurea is an oral chemotherapy medication that decreases the production of neutrophils from your bone marrow. If hydroxyurea is not helpful in managing your symptoms or is causing you too many side effects such as nausea, vomiting, diarrhea, leg ulcers, flu-like symptoms, bone pain, and loss of appetite, your doctor may change the medicine to Interferon alfa-2b (Intron A). Interferon is given by injection and works by decreasing the specialized neutrophil-forming cells in your bone marrow.
- If your cancer is more aggressive, you can expect to get chemotherapies such as Cladribine, thalidomide, and Ruxolitinib but usually these medications work only for some time and your disease may come back.
- A bone marrow transplant can potentially cure your CNL. It is a medical procedure by which healthy bone marrow cells from bone marrow donors are transplanted into your bone marrow or your blood. This procedure is reserved if your neutrophil counts remain high despite the medications listed above, or if you develop acute leukemia. Your doctor will determine on a case-by-case basis to determine if you are a candidate for a bone marrow transplant.
It is important to have regular follow-ups, and blood tests with your doctor. Currently, several clinical trials are ongoing to target the mutations associated with CNL. Your doctor is the best person to make this assessment and guide you in the enrollment of clinical trials.
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