A 35-year-old woman comes to the physician after finding a small mass in her right breast when performing a self-examination while taking a shower. Mammogram shows mass about 1 cm in diameter slightly above, and lateral, to her right areola. She underwent lymph node biopsy and a specific dye was injected into the tissue around the tumor, which was taken up by the lymph vessels, draining the area. The vessels were traced to surgically expose the lymph nodes receiving the lymph from the tumor. Which nodes will most likely first receive lymph from the tumor?

A 41-year-old woman comes to the physician for a lump in her right breast. Physical examination shows dimpling of skin of the breast over the mass. A CT scan of the breast shows a 3-cm mass at the right upper quadrant of her right breast with multiple calcifications. The dimpling of the breast is most likely caused by invasion of the tumor into which of the following structure(s)?

A 48 year old woman presents for evaluation of a small mass next to her right nipple. She has also noticed a small amount of discharge over the past week. On physical exam, you palpate a 1 cm round nodule beneath the areola and notice some clear discharge. Breast examination is otherwise normal and no lymph nodes are palpable. A lesion biopsy reveals intraductal papilloma without atypia or malignant cells. Which of the following is true regarding this lesion?

 A 23 year old woman presents with a 1 cm mass on her left breast. The mass is firm, painless, and freely movable. Since discovering the mass, the patient has not noticed a change in its size. A histological examination of the mass reveals layers of ductal cells with dense stroma. Which of the following is the most likely diagnosis?

A 52-year-old woman underwent mastectomy for invasive ductal carcinoma of the left breast. During the procedure the tumor and the pectoral, central axillary, and apical axillary lymph node groups were excised. Six months later she comes to the physician for a follow-up examination. Physical examination shows a deep, hollow area inferior to the medial half of the clavicle. The patient has no motor or sensory deficits. Which of the following is the most likely cause of the findings on physical examination?