Dear gingermoore, Decisions about need for further investigation such as biopsy are based on degree of suspicion of a mass. This degree of suspicion is determined based on the findings of history and physical examination, findings of the tests etc. It is impossible for us to make specific recommendations over the internet as to whether a biopsy is needed in your situation, and if so what type of biopsy makes the most sense. These are questions best asked of the specialist who with all of the information available will be able to discuss in context of your individual situation.
I would think that the lymph node swelling might put up a red flag along with the mass though.
They say 80% of all masses are benign. I unfortunately am in the other 20% , but I had a hige mass as well as microcalcifications on mammo that is why my biopsy was ordered, because of the microcalcifications rather then the mass. So push for an answer that your comfotable with.