The spleen is one of those organs that everyone has heard of and knows is important but doesn’t quite understand in terms of how it works or what it really does. Unlike the lungs or the heart that we feel evidence of every time we breathe or feel our pulse, the spleen quietly toils deep in our abdominal cavity, and we’re pretty much oblivious to whatever activities it is engaged in. 

The fact is, though, that a fully functioning spleen is an important part of our everyday health and wellbeing, most notably with regard to immune function. While you can technically live without a spleen, the resulting increased risk of infection and disease makes its loss a dangerous possibility. One of the conditions, though relatively rare, that can potentially lead to the need for removal is an enlarged spleen.

What Does the Spleen Do? 


Before you can understand the circumstances surrounding an enlarged spleen, it’s helpful to first understand what the spleen actually does. Located below the rib cage and behind the stomach, the spleen is the largest organ of the lymphatic system. In essence, the spleen is a part of the immune system that filters blood as it circulates throughout the body. Along with the lymph nodes (another part of the lymphatic system), the spleen prevents disease and fights infections by removing toxins and cellular waste from our bloodstream. 

 The majority of the work done by the spleen is through the process of regulating the number of red blood cells we have in our blood. It also stores platelets, another component of our blood, which the body uses to form blood clots in the event of an injury. The regulation of red blood cells and platelets is important for overall body health in the sense that our blood needs to be efficient in carrying oxygen to all parts of the body; when the spleen is functioning properly, our immune system can respond more rapidly when injury or disease is detected.  

Another critically important function of the spleen is to store white blood cells, also known as lymphocytes. White blood cells are another part of the body’s immune function, and they are the first line of defense against an infection. When infection is detected, the spleen releases these lymphocytes into the bloodstream, and they seek out foreign elements (like bacteria) and attempt to eliminate them. 

What Causes an Enlarged Spleen?


There are a variety of reasons why a spleen might become enlarged, but the basic mechanism is generally some kind of buildup or clot of either the waste materials the spleen is supposed to be filtering out or an overload of the blood components that it regulates. The condition, technically known as splenomegaly, is considered a secondary condition because it is almost always a symptom of some other underlying problem. In fact, splenomegaly is considered one of four signs of an overarching illness called hypersplenism, a disorder that is characterized by the spleen being overactive. 

Even though there are many different potential underlying causes that can lead to an enlarged spleen, there are a few possibilities that will tend to be the likely culprit. Here are some of the most common causes of splenomegaly:  

  • Blood disorders: Since one of the spleen’s primary functions is to filter blood, disorders that involve the damage or overproduction of red blood cells can eventually lead to an enlarged spleen. Damaged red blood cells, when detected by the spleen, are removed from the bloodstream and broken down. In some blood disorders, though, the spleen can’t break the damaged cells fast enough; as a result, the spleen swells with the additional buildup of cells.
    • Hemolytic anemia: a condition where red blood cells become damaged
    • Sickle cell disease: red blood cells become misshapen and then are subsequently broken down by the spleen 
    • Thalassemia: red blood cells with decreased hemoglobin are filtered out by the spleen
    • Spherocytosis: a condition where red blood cells are spherical rather than the normal disc shape; this shape can lead to damage and then filtering by the spleen
  • Decreased blood flow: When an underlying condition causes a decrease in blood flow through the splenic vein, the resulting imbalance can cause pressure to build and blood to back up, resulting in splenomegaly. 
    • Liver disease: damage to the liver (for any number of reasons) can cause problems with normal blood flow
    • Congestive heart failure: the central problem of the heart not pumping blood as well as it should can cause problems with blood flow that, in turn, can lead to both an enlarged liver and an enlarged spleen   
  • Cancer: There are numerous cancers that can affect the spleen specifically or the various components of our blood. Cancers that affect the blood involve abnormal or damaged cells that are then targeted by the spleen for filtering. 
    • Leukemia: a cancer of blood-forming tissues, especially bone marrow, that generates large numbers of abnormal blood cells  
    • Lymphoma: a blood cancer that develops in lymphocytes, a type of white blood cell the lymphatic system sends out to fight disease 
  • Metabolic diseases: This set of diseases is characterized by the abnormal conversion of substances in the body; since this process occurs on the cellular level, the resulting damage can be filtered out by the spleen.
    • Hurler Syndrome: a genetic disorder that allows abnormally large sugar molecules to form in the body and subsequently cause damage to various organs, including the spleen
    • Gaucher disease: a genetic disorder where a deficiency in a certain enzyme can lead to buildup of harmful elements in white blood cells
    • Niemann-Pick Disease: a disorder involving the buildup of lipids in the spleen (and other organs) due to an enzyme deficiency
    • Sarcoidosis: collections of inflammatory cells that often begin in the lymph nodes and then build up in the spleen
    • Amyloidosis: abnormal protein buildup in various tissues in the body, including the spleen
  • Infection: There are numerous infections that can ultimately affect the spleen in some capacity of its immune system function.
    • Infectious mononucleosis (caused by the Epstein-Barr virus)
    • HIV/AIDS
    • Malaria 
    • Tuberculosis
    • Cytomegalovirus
    • Viral hepatitis
    • Anaplasmosis
  • Trauma: Damage due to trauma, such as in a car accident, can cause the spleen to enlarge for a variety of reasons. Trauma can also cause the spleen to rupture.

Symptoms of an Enlarged Spleen


Most people who have an enlarged spleen actually don’t experience any direct symptoms, because the enlargement itself isn’t something that can be felt. As a result, most people don’t even know they have an enlarged spleen until it is discovered in an exam for some other problem. 

The symptoms typically involved in an enlarged spleen are usually related to the underlying cause, such as fatigue and shortness of breath in anemia, for example. For those who do experience symptoms, the most common examples are discomfort or pain in the upper left side of the abdomen or an inability to eat large meals. More than likely, though, a person with an enlarged spleen will seek out a doctor’s diagnosis for some other reason and then the doctor will find evidence of splenomegaly. 

What is the Treatment for an Enlarged Spleen?


The treatment options for an enlarged spleen depend almost entirely on the underlying cause and the severity of those symptoms. Most of the time, the resolution of the underlying cause will, in due course, solve the spleen problem. In general, though, an enlarged spleen is in danger of rupturing; for this reason doctors will recommend avoiding sports or any activities where trauma could occur.

In severe cases, as in lymphoma or situations where the spleen’s size starts to become destructive to platelets and red blood cells, surgery may be required. This procedure, known as a splenectomy, involves removing all or part of the spleen. As noted earlier, you can live a full and normal life without a spleen; however, the lack of spleen means that your immune system will be compromised for the rest of your life. In order to compensate, doctors will prescribe a series of regular medications to boost immune function.

Gastroenterologist Appointment


The spleen is an important organ that can’t be overlooked, but unfortunately, you probably won’t know if it becomes enlarged. This is why it’s important to make regular visits to the doctor to make sure you’re in good health. If you would like more information about a possible enlarged spleen, or if you would like to talk with a gastroenterologist about your health in general, contact Cary Gastroenterology Associates to make an appointment.