Alan, I an sadden to hear this diagnosis.
Let's hope that it is a minor and something that can be taken care of simply. I too would wait to tell the kids until the doctors have most of the test back and truly know what is happening with you, there is no reason to worry them quite yet.
You are a strong individual and stubborn, so I know you will fight this.
Stay strong my friend and know that you and Peggy are in our thought and prayers.