mass in neck of pancreas

I am a 45 year old female.I was diagnosed with a 3cm fluid filled mass imbedded in the middle of my pancreas. I had a surgical consult, and the surgeon does not believe it is cancer. He wants to remove it because he said that they often turn into cancer.  He will have to remove 60% of my pancreas and my entire spleen. My question is, is it normal to have to remove the spleen with a resection of a mass in the body of the pancreas? The surgeon has started me on a series of vaccines (pneumovaz, H. flu, and menegial coccus) to boost my immunity before losing my spleen. Should I seek a second opinion? He said he does not wish to biopsy the mass before removing it because it will leak into my abdomen and cause problems. Has anyone ever heard of losing the spleen with pancreatic surgery? Thank you!