When most of us think of cancer, we envision a defined lump in our breast or a single polyp in our colon. We think of cancers as solid growths that we can feel or that block, bleed, or in some other way clearly point themselves out. But there are a group of cancers that do not always (or even ever) develop as solitary tumors, that are fluid-like, and that produce misleading symptoms which make their diagnosis challenging. These are the “liquid tumors,” or “blood cancers,” known commonly as leukemia and lymphoma. And you can easily learn what symptoms to look for as these malignancies try to hide within your body.
How Leukemia Develops
While common in children, leukemia is rare in adults, representing just over 3% of all malignancies as the 11th most common cancer in the U.S. To understand leukemia, you must first understand your bone marrow, the sponge-like tissue living within the bones of the adult pelvis and the sternum.
The bone marrow is an amazing blood cell and blood-component factory, turning undifferentiated stem cells into your red blood cells (critical for carrying oxygen throughout your body), platelets (non-cells important in blood clotting), and white blood cells (immune cells which fight infection) which are then released into your bloodstream.
Leukemia develops when a white blood cell within the bone marrow becomes malignant. That one immortal cancer cell divides and divides and divides, its daughter cells filling the bone marrow and destroying surrounding normal blood cell development. Nor do the malignant white blood cells just stay within the bone marrow, pouring out (often in huge numbers) into the bloodstream.
With No Solid Mass, More Places to Hide
But there is no leukemia “tumor.” No growth to feel or to block urine or stool passage or to cause site-specific bleeding. Leukemia is great at hiding, only leaving general clues to indicate that something is wrong. We call such symptoms “non-specific;” that is, whatever you’re feeling or however your body is acting that is not right, these abnormalities don’t clearly point to the diagnosis (or even suspicion) of leukemia. Chronic fatigue, recurrent fevers or chills, infections that hang on or quickly return, unexplained weight loss, significant sweating (especially during the night), nosebleeds, or easy bruising. These are the most common symptoms of leukemia. So it’s easy to see why patients often wait a long time before seeing a physician, believing that these body issues are no big deal and/or will soon pass.
There are several types and subtypes of leukemia, along with an individual’s disease stage and other factors influence treatment options. Prognosis (survival with and without disease) also varies significantly by type, sub-type, and disease stage, but overall at 5 years, 58.5% of adult leukemia patients are alive (with or without disease).
Lymphoma Presents in Liquid or Solid Form
Unlike leukemia, lymphoma can both hide in liquid form and/or grow as a solid tumor, because the white cell that becomes a malignant lymphoma develops within an immune system structure such as a lymph node. Your immune system (composed of lymph nodes and lymph vessels) empties directly into your circulatory system, so lymphoma cells rapidly find their way into the bloodstream. And from the bloodstream, lymphoma cells can infiltrate the bone marrow.
When lymphoma remains as a “liquid tumor,” cancer produces the same non-specific symptoms as does leukemia. Thus lymphoma acting as a “blood cancer” may mislead a lymphoma patient to delay medical evaluation. Fortunately (and unlike leukemia), lymphoma can also present as a solid (and easily detectable) tumor.
Most often, solid lymphoma presents as one or more swollen lymph nodes in the neck, the armpit, the groin, or elsewhere. It is important to appreciate that everyone gets swollen lymph nodes many times throughout our lives as our bodies fight common infections. Thus, when you have a sore throat, you often find those tender, swollen lumps in your neck and under your chin. And if you have a cut on your arm or leg, you may find painful-to-touch lumps on the same side as your injury in your armpit or groin, respectively.
But unlike these benign (and functioning) lymph nodes, malignant lymphoma nodes are painless. And also unlike normal, infection-fighting lymph nodes, cancerous nodes continue to enlarge over time. (In addition, one form, non-Hodgkin lymphoma, can present as swelling of or pain in the abdomen, as cancerous cells can fill and enlarge the spleen.)
While there are several types of leukemia, there are two major lymphoma categories: Hodgkin and non-Hodgkin lymphoma (NHL). Hodgkin lymphoma is rare, representing only 0.5% of all U.S. adult cancers and, fortunately, is extremely treatable, with close to 86% of patients alive (with and without disease) at five years. NHL is the much more common form and is the 7th most common malignancy, representing just over 4% of all new cancers in the U.S. Survival five years after diagnosis (with and without disease) is 70%.
The one key to survival from leukemia and lymphoma that is in your control is an early diagnosis. While leukemia and some lymphomas are great at hiding as “liquid tumors,” knowing the non-specific symptoms of these “blood cancers” is a good way to protect your health.