Features:
(1) premenopausal women with long-standing, insulin-dependent diabetes mellitus; rarely may occur in men
(2) patients may have microvascular complications (retinopathy, nephropathy, neuropathy), associated with the duration of the diabetes
(3) patients may have concurrent autoimmune disorders with autoantibodies (to thyroid, parietal cells, etc).
(4) firm/hard nodular mass(es) in the breast, mobile and painless
(5) ultrasonography often shows marked acoustic shadowing
(6) mammograms show dense lesions without features of malignancy
(7) fine needle aspirates often are non-diagnostic
(8) dense stromal fibrosis, which may be keloidal
(9) dense lymphocytic infiltrates, with periductal (ductitis), intralobular, perilobular (lobulitis), and perivascular (vasculitis) distributions, composed mostly of B cells
(10) fibroblasts may be atypical and hyperchromatic, or "epithelioid"
(11) may recur after excision
(12) not associated with an increased risk for neoplasia
Differential diagnosis:
(1) chronic lymphocytic mastitis in nondiabetic patients (lymphocytes mostly T cells)
(2) fibromatosis
