Spleen Diseases

The spleen is an organ located in the upper left side of the abdomen, just behind the stomach and below the diaphragm. Until recently, scientists weren't quite sure the exact function of this organ. We now know it serves to help in the removal of old or damaged red blood cells as well as assist the immune system [Page 1598]in protecting our body from infections, both viral and bacterial. The spleen does this by filtering blood through a series of complicated sinuses and capillaries, removing old and damaged red blood cells from circulation. Foreign compounds like bacteria come in contact with lymphoid (immune system) tissue inside the spleen and activate the rest of the immune system as well as being removed from the body. The spleen may be predisposed to a certain set of diseases because of its function, mainly a problem called splenomegaly, or enlargement of the spleen.

Splenomegaly can be caused by quite a few problems, ranging from insignificant to extremely serious and life threatening. Some of the causes of splenomegaly are infection, hematologic disorders, congestive splenomegaly, storage diseases, and others. Infection is the most common cause of splenomegaly, and can be acute or chronic depending on the etiology of the infection. Acute splenomegaly can be caused by a bacterial abscess, brucellosis, infectious mononucleosis, cytomegalovirus, or typhoid fever. Basic medical work-up of acute splenomegaly should include a complete blood count with differential, platelet count, reticulocyte and atypical lymphocyte counts. It is important to rule out more serious causes of acute splenomegaly such as hemolytic anemias and leukemia. Chronic splenomegaly can be caused by echinococcosis, histoplasmosis, malaria, syphilis, or tuberculosis. The hematologic disorders that can cause splenomegaly are hemolytic anemias, thalassemias, sickle cell disease, leukemias, lymphomas, multiple myeloma, myelofibrosis, polycythemia vera, structural hemoglobinopathies, or thrombocytopenic purpuras.

Congestive splenomegaly can be caused by cirrhosis of the liver, stenosis of the splenic vein, portal vein, or hepatic vein, and heart failure. The spleen is enlarged because blood cannot be removed efficiently because of increased pressure in the venous draining system. Storage diseases that cause enlargement of the spleen are Gaucher's disease, Niemann-Pick disease, and mucopolysaccharidoses.

These storage diseases manifest by an excess amount of fat or carbohydrates being deposited in the spleen, reducing its ability to function properly. Some other common causes of splenomegaly are amyloidosis, berylliosis, Felty's syndrome, Graves’ disease, histiocytosis X, sarcoidosis, or systemic lupus erythematosus.

There are a few treatments of splenomegaly. The first stage in treatment is trying to reduce the symptoms associated with the diseases that cause the spleen to be enlarged in the first place. This may include the administration of antibiotics, antimalarials (hydroxychloroquine), corticosteroids, immunosuppressant, blood transfusion, chemotherapy, enzyme replacement therapy, or even surgical intervention may be necessary. If these don't help resolve the splenomegaly it may be necessary to completely remove the spleen, this procedure is called splenectomy. Once the spleen is removed, the patient is considered immunocompromised and should be put on prophylactic oral antibiotics for life.

Cysts and tumors may also cause diseases of the spleen. Cysts are infrequent and they usually don't cause much of a problem except for diminished function due to lack of normal tissue. Tumors of the spleen are not very common either, but if they do occur, they may cause serious problems.

...