What Is an Accessory Spleen?

An accessory spleen is one or more additional spleens that grow in addition to the primary, full-sized spleen. These spleens are usually much smaller in size, measuring no more than a three centimeters in diameter. Some accessory spleens function as regular spleens do, while others simply grow and function as tumor-like masses.

Frequency

• According to the Medical College of Wisconsin, accessory spleens occur in 10 to 30 percent of the population, and less then ten percent of patients with an accessory spleen will have more than one.
  Accessory spleens are usually found in the abdomen, though some male patients have had accessory spleens in the area of the testes.

Causes

• Many cases of accessory spleen are triggered by abdominal trauma, particularly trauma that caused splenic rupture. In other cases, there is no known cause for an accessory spleen.

Symptoms

• There are often no telltale signs of an accessory spleen. Unless a diagnosis for anemia, abdominal pain or suspected internal bleeding is sought, the accessory spleen may never be discovered, or if it is, it will be discovered by accident. Scans and ultrasounds done for other medical purposes may alert your physician to the presence of an accessory spleen in your body.

Risks

• On their own, accessory spleens are not usually harmful and can be left alone, so long as they remain in the abdomen. But if there is pain, or a risk or indication of an infarction (tissue death caused by a lack of blood supply), a rupture or a vascular torsion (a twist in the structure), surgery will be recommended.

Treatment

• Accessory spleens can be removed using a laparoscopic surgical procedure known as a splenectomy. The surgery is minimally invasive, and most accessory spleens can be removed without causing much disturbance to any nearby organs or tissues. However, if an accessory spleen is not causing any problems to the patient, surgery will not be a recommendation, simply because treatment isn't necessary.