I would see an oncologist with any diagnosis that has the word cancer in it. I also wouldn't consider that something is cancer until I hear it from a top-notch oncologist.

I've had three friends told they had cancer by doctors without the education, training and experience to offer more than a casual 'maybe' opinion. And all three doctors were wrong.

The sooner you have an oncologist looking into this, the sooner something can be dealt with if merited.

Your PCP should be of help in getting a referral in place. And might have some input as to what s/he thinks as well.