A 46-year-old female comes to surgery OPD with complaints of lump felt in breast. On examination, the lump was confirmed, which had irregular margins and was hard in consistency. The nipple was retracted as well. Mammography was done which revealed the lesion as shown below. HPE was done as well which confirmed the nature of the lesion. Gross finding is shown below. Which structure is responsible for the finding?

HPE image is suggestive of DCIS-NOS. A- Pectoralis major B- Lactiferous ducts C- Suspensory ligament D- Subdermal lymphatics The image given above depicts circumferential retraction of nipple which occurs due to involvement of lactiferous ducts. Subdermal lymphatics involvement/blockade will give rise to peau d' orange (orange peel) appearance. Ligament of cooper involvement causes dimpling and puckering of breast skin. Pectoralis major muscle involvement causes the tumor to be fixed when the muscle is contracted.