Benign well encapsulated tumors formed of proliferating breast ducts and stromal fibrocytes. In areas both component are represented equally (pericanalicular pattern) however, in other areas fibroblastic proliferation dominates thus compressing ducts into slit-like structures (intracanalicular pattern). No evidence of malignancy.
Right breast masses.
Two fibrofatty tissue pieces measured 4.5x3x2.5 cm and 3x3x2.3 cm. Serial sectioning revealed well defined rubbery whitish mass in each, measuring 3.8x2.5x2.3 cm and 3x3x2.3 cm.
Right breast masses, excision biopsies: