A 70-year-old woman has a 2-cm mass in the left breast. The patient's physician recommends that a core needle biopsy be performed. Tissue analysis reveals the following finding. She is advised by the surgeon to have surgery to remove the primary breast mass in addition to some lymph nodes. The patient undergoes wide excision of the breast mass and lymph node removal. Which lymph nodes are most likely to be affected?

A- Cervical lymph nodes B- Axillary lymph nodes C- Interpectoral lymph nodes D- Infraclavicular lymph nodes This 70-year-old woman had a palpable breast mass. Pathological examination revealed intra-ductal carcinoma in the core needle biopsy. Risk factors include the patient's age, and intraductal carcinoma is the most common histological type. The most common treatment plan would be a breast-conserving procedure such as a lumpectomy (excising the malignant mass with some margins) and axillary lymph node dissection. The presence or absence of malignant cells in the axillary lymph nodes is the single most impoant prognostic factor for survival.