Hi Daisy, sorry to hear about your mum's dx. I'm glad I had SNB (two years ago) because it reduced my risk of lymphodema. If SN is affected they will continue and do a full node clearance.
Info from breastcancercare:
http://www.breastcancercare.org.uk/breast-cancer-information/treating-breast-cancer/surgery/surgery-...This page from breastcancer.org explains:
"In 2014, the American Society of Clinical Oncology released guidelines on sentinel lymph node biopsy. The guidelines say sentinel lymph node biopsy SHOULD be offered under these circumstances:
breast cancer in which there is more than one tumor, all of which have formed separately from one another (doctors call these multicentric tumors); these types of breast cancers are rare
DCIS treated with mastectomy
women who have previously had breast cancer surgery or axillary lymph node surgery
women who have been treated before with chemotherapy or another systemic treatment (treatment before surgery is called neoadjuvant treatment)"
http://www.breastcancer.org/questions/sentinel_nodeBig hugs and best wishes
x x