The spleen is an organ you don't hear that much about, yet it performs several important functions. It removes damaged red blood cells and it keeps a reserve of blood ready to be used if your blood pressure drops too low. It keeps a reserve supply of recycled iron, ready to be used again when new red blood cells are made. And as Drs. Delves and Roitt state in the Jul. 13, 2000 issue of the "New England Journal of Medicine," the spleen also initiates the body's immune system. But there are a variety of conditions that can cause problems for the spleen, causing it to enlarge.
Sickle Cell Anemia
Sickle cells cause problems, because their shape interferes with the normal flow of blood inside the spleen. This then causes the spleen to enlarge, and you can go into shock because not enough blood is circulating throughout your body. This problem is called a splenic sequestration crisis, because the red blood cells are sequestered, or held, inside the spleen. But sickle cells will cause another problem for the spleen. Because they obstruct blood flow, the spleen will not get enough oxygen for itself.
Infectious Mononucleosis
This infection is caused by a virus named Epstein-Barr. If you contract mononucleosis, you will have a fever, sore throat, swollen lymph nodes and will usually feel extremely tired. But you will also have a problem with your spleen. Your bone marrow will make a lot of white blood cells to fight against the virus. Many of them will be referred to as atypical due to their structure, and will fill up your spleen, causing it to enlarge. This is a problem because until it returns to its normal size, any trauma to the spleen from contact sports can cause it to rupture.
Portal Hypertension
Anything that interferes with the normal flow of blood into and out of the liver can cause portal hypertension. It is called this because the obstruction causes blood to be backed up in the portal vein, which causes the pressure inside that vein to increase. But the portal vein is also connected to the spleen, so its backup and increased pressure can cause blood to be backed up in the spleen. This can cause the spleen to enlarge. The most common reason for this to happen is cirrhosis, but it can also be caused by inflammation, scarring and blood clots.
Leukemia
Leukemia is a type of cancer where there are very high numbers of white blood cells circulating throughout your bloodstream. There are so many of them in your bone marrow that they crowd out the other types of blood cells. As a result, the low number of red blood cells can cause you to become anemic, while the low number of platelets can cause you to hemorrhage. But leukemia also causes a problem with your spleen. Similar to mononucleosis, these white blood cells will also infiltrate your spleen and cause it to greatly increase in size.
Gaucher's Disease
Gaucher's Disease is a hereditary disease where your body does not have enough of a particular enzyme (called beta-glucocerebrosidase). Without this enzyme, certain lipids accumulate in some of the cells of your spleen, brain, liver and bone marrow. The most common type of this disease does not involve the brain; however, as an adult, you will have an enlarged spleen as well as bone pain and possible fractures.
References
- "New England Journal of Medicine"; The Immune System---Second of Two Parts; Peter Delves, PhD, Ivan Roitt, PhD; July 2000
- "Robbins Pathologic Basis of Disease"; Ramzi Cotran, M.D., Vinay Kumar, M.D., Stanley Robbins, M.D.; 1994
- WebPath: Splenomegaly
