Armpits Lymph Nodes and a Benign Tumor?

My aunt went to the doctor to check out her breast The doctor noticed in the X-ray that she had a (Fatty Cyst) in her breast, she told her its not something serious, but she should check it with another Professional doctor (he was a bone doctor) We went to take another examination with another doctor.. After checking out the results of the images, he said that she have a Benign tumor in her breast and some swallowen lymph nodes in her armpit.  He said that's its completely normal and she should not worry about it.

Now I've read on the internet that the only way to know that the tumor is Benign is to take biopsy, which the doctor didn't do.
And I've never heard of lymph nodes coming along with Benign tumors (I heard it only comes with Breast Cancer)

Please clear my doubts, My aunt already went to 2 doctors and I am still worried.  She is in her 50s.

[japdip]

Lymph nodes can become swollen for many reasons other than a connection to cancer. It is true that a biopsy is necessary when a mass of undetermined origin is found but cysts have chacteristics that can be seen on film and a biopsy is rarely required. Simple cysts are benign and as a rule need no treatment. They can be removed if they are terribly troublesome by being very large or causing considerable pain. The enlarged lymph nodes don't even need to be related to the cystic condition; they can become enlarged due to some minor infection somwwhere in the body .... that is their job. The tumor may be either a true cyst (containing fluid) or a Fibroadenoma (solid), both of which are benign.  Kindest regards ..