What are the causes of pain, itching and sensitivity in breasts?

I am in my 50's. For months I had a large localized area of deep pain in my breast. The Doctor examined me and found nothing, and a mammogram was negative.  I have large, dense breasts and the mammogram was difficult to do.  As the pain did not abate, I requested an ultrasound. The doctor said I did not need one as the mammogram was negative. The pain has now developed into a deep itching (not the skin!) within that area where the pain was. It is now very uncomfortable for clothing to touch my chest and I am aware of the discomfort constantly.  Prior hx includes 2 biopsies on that breast in the '90s, one a fat necrosis and the 2nd scar tissue. I also had severe bruising to the chest wall due to a car accident prior to the biopsies. Family hx includes breast cancer (maternal aunt) and cervical cancer (Mom and sisters). What are some of the causes for pain and progression to nerve pain in the breast? Would a ultrasound be of any value?

[Cleveland Clinic]

Dear mlaurel:  There are many possible explanations for breast pain that could not possibly be listed in any way on the internet as to give you an idea what the explanation may be in your situation.  Whether an ultrasound would be of value is unknown.  You may benefit from a second opinion from a medical breast specialist (often affliliated with large academic medical centers) who could evaluate your situation and determine what testing would be appropriate in your situation.

[mlaurel]

Thank you for your previous reply. I have seen a doctor at a larger Medical center. The doctor was readily able to feel a lump but the mam and us did not show anything. I am waiting to hear from the doctor. Is it common to have a lump that is not visible on mammograms and/or ultrasounds?