Your Spleen.

[estranged4life]

I dont think it is useless since it is the largest "lymphnode" in your body, and it does have a use:

"The spleen is a ductless, vertebrate organ that is closely associated with the circulatory system, where it functions in the destruction of old red blood cells and holding a reservoir of blood. It is regarded as one of the centers of activity of the reticuloendothelial system. Until recently, the purpose of the spleen was not known. It is increasingly recognized that its absence leads to a predisposition to certain infections."