Cancer that first starts in the spleen is a rare occurrence.

Researchers believe it happens in less than 2 percent of all lymphomas and 1 percentTrusted Source of all non-Hodgkin lymphomas.

A form of cancer that does develop in the spleen is called splenic marginal zone lymphoma or SMZL, which is considered a kind of non-Hodgkin lymphoma.

Since most cancers affecting the spleen are cancers that spread from another place, understanding the causes of spleen cancer means looking at what causes these other diseases.

Most cancers that start in the spleen are a kind of lymphoma or leukemia. Most of the time, it is not possible to find a specific cause of lymphoma, according to Lymphoma Action.

Researchers have, nonetheless, identified factors that may increase the risk of developing lymphoma, including:

• being older
• being male
• having a relative with lymphoma
• having immunity complications
• being exposed or vulnerable to infections

Several studies have identified a linkTrusted Source between chronic infection with the hepatitis C virus, and the risk of developing a specific kind of cancer known as B-cell non-Hodgkin lymphoma, which can lead to spleen cancer.

Researchers have also identified possible links between spleen cancer and environmental hazards, such as thorium dioxide or monomer vinyl chloride.

People with spleen cancer can have a variety of symptoms or none at all in some cases. Roughly 25 percent of people with SMZLTrusted Source do not show symptoms.

The most common symptoms of spleen cancer are:

• enlarged spleen, which may become twice as large as normalTrusted Source
• pain in the abdomen, usually in the upper left corner
• weakness
• unexplained weight loss
• fatigue
• fever
• night sweats
• high levels of lymphocytes in the blood

It is essential, however, to remember that an enlarged spleen does not necessarily mean that an individual has spleen cancer.

Spleen cancer is very often due to lymphomas and non-Hodgkin lymphoma in particular, so it is helpful to be aware of signs of this disease.

Signs include:

• swollen, but usually not painful lymph nodes in the armpits, groin, and sides of the neck
• feeling exhausted
• alternating chills and fever
• bruising easily
• frequent infections
• swollen, sometimes sore, belly
• poor appetite
• feeling full on very little food
• losing weight without trying

People with any of the symptoms listed above should see a doctor for checks and treatment if it is necessary.

Keep in mind that some thing other than cancer many cause these symptoms. For example, an infection can lead to swollen lymph nodes.

Since there is no screening test for spleen cancer, and the disease can develop without symptoms, it is always wise to have a doctor check any signs that are concerning.

Doctors use a variety of tools to diagnose spleen cancer. The most direct and conclusive method is surgical removal and testing of a sample of the spleen tissue. This is also the most invasive, and doctors prefer to use other approaches first.

Alternatives include:

• taking a comprehensive medical history
• imaging with ultra-sound or tomography
• requesting blood work
• arranging bone marrow analysis

Doctors will be looking for clues to help them diagnose and possibly treat spleen cancer while interviewing the individual about:

• history of chronic hepatitis C or B
• history of autoimmune diseases
• treatment with immune-suppressing medication
• signs of a significantly enlarged spleen

Common treatments for spleen cancer include:

• surgery called splenectomy that removes part of or the entire spleen
• radiation therapy
• chemotherapy

Historically, splenectomy was often the first treatment used, and studies have shown that most peopleTrusted Source who had this surgery did not need any further treatment for 5 years.

However, treatment with a human-made antibody called rituximab has been shown to be almost as effective as surgery at reducing symptoms in people with SMZL. Also, it may be easier to use than surgery.

Individuals without symptoms do not necessarily need to receive treatment, but they are urged to see their doctor every 6 months for blood tests and evaluation. This approach is sometimes called “watchful waiting.”

Doctors have linked chronic hepatitis C infections to spleen cancer and other forms of non-Hodgkin lymphoma. So, taking action to avoid Hepatitis C can help people reduce their risk of this disease.

Hepatitis C is carried in the blood, so it is essential to:

• Use caution when getting a tattoo or piercing and be sure equipment is sterilized.
• Use condoms if having sex with a person who has not been tested for hepatitis C and other sexually transmitted diseases.
• Follow safety procedures for using and disposing of needles in a healthcare setting.
• Never share needles.

Infection with HIV and HTLV-1 may also increase the risk of developing non-Hodgkin lymphoma and spleen cancer. Following safe sex guidelines and the same preventive measures used against Hepatitis C can be effective against carrying these viruses.

Eating a lot of high-fat foods, and the resulting excess weight gain, have both been linked to a greater risk of developing non-Hodgkin lymphoma.

Adopting a healthful, low-fat diet and maintaining a suitable weight are positive self-care practices that can reduce the risk of developing many other serious and chronic diseases too.

The outlook for people with spleen cancer depends on:

• If it developed in the spleen or originated elsewhere in the body.
• What type of cancer it is.
• How far advanced the disease is.
• What other health problems the individual may have.

SMZL is described by scientists as “indolent,” which means it usually grows slowly, and has a positive influence on overall outlook. About 30 percentTrusted Source of the time, however, individuals develop a more aggressive form of the disease.

For a more personalized outlook, people should see their doctor, as soon as symptoms present themselves.