**1. Introduction**

"The spleen" whose weight once thought to have been hindering the speed of runners to its role in cleansing process as its absence could result in the loss of laughing ability was called the "mysteriipleniorganon". Its biological function has been elusive for thousand of years and also had been assumed to have no vitality in life. It's been centuries since its existence has been under tremendous perusal and it wasn't until mid-twelfth century when the concept of blood purifying function was emphasized. In early 1900, however, numerous experiments have concluded its role in the host defense and immune function. Spleen surgery dates back to 1549. Zaccaelli carried out the first splenectomy in this year. In 1952, King and Schumaker reported the overwhelming postsplenectomy infection (OPSI) in children with hereditary spherocytosis who had undergone splenectomies, which caused a wide concern on the potential function of the spleen.
