Ask the experts
I have a problem in regard to my spleen (or I should say "spleens"), because I have an extra spleen. Doctors call it (an accessory spleen). Should I be concerned about this extra spleen?
Occasionally individuals are born with more than one spleen. In fact, the total amount of splenic tissue in these individuals is about the same as in an individual with a single spleen, but the tissue is separated into two (sometimes more) separate pieces. One piece often is smaller than the other and is referred to as an accessory spleen. Multiple (accessory) spleens do not cause medical problems, and nothing is done about them. Rarely, accessory spleens may be confused with tumors. They usually can be definitely identified by radionuclide liver-spleen scans.
"Approach to the adult patient with splenomegaly and other splenic disorders"