Accessory spleens are found in approximately 10 percent of the population[1] and are typically around 1 centimetre in diameter.

[2] They are medically significant in that they may result in interpretation errors in diagnostic imaging[2] or continued symptoms after therapeutic splenectomy.

[12] Splenosis is a condition where foci of splenic tissue undergo autotransplantation, most often following physical trauma or splenectomy.

Displaced tissue fragments can implant on well vascularized surfaces in the abdominal cavity, or, if the diaphragmatic barrier is broken, the thorax.

[1] During medical imaging, accessory spleens may be confused for enlarged lymph nodes or neoplastic growth in the tail of the pancreas,[5] gastrointestinal tract, adrenal glands or gonads.