A 50 year old postmenopausal woman presents with a lump in her left breast for 2 months. There was no associated pain or recent rapid enlargement. There is no history of previous breast disease, or a family history of breast, bowel or ovarian malignancy. She is nulliparous, while her menarche was at age 12. She was diagnosed with type 1 diabetes at age 20, which is now complicated by diabetic retinopathy, nephropathy and peripheral neuropathy.
There is dense glandular tissue in both breasts, more on the left side. No discrete nodules are seen; there are no microcalcifications; architectural distortion is absent.
There is a poorly defined, irregular lesion of mixed echogenicity in the lower inner quadrant of the left breast; posterior acoustic shadowing is present. The right breast appears normal.
Firm resistance felt during biopsy; samples obtained are inadequate. Only a few ductal cells without atypia are noted.
There is a dense fibrous stroma consisting of thick bundles of collagen with keloid-like features. Lymphocytic lobulitis and perivascular lymphocytic infiltration without evidence of malignancy is seen.