title: What Is a False Negative Sentinel Node Biopsy: Definition, Reasons and Ways to Minimize It?
abstract: Sentinel node biopsy helps in assessing the involvement of axillary lymph node without the morbidity of full axillary lymph node dissection, namely arm and shoulder pain, paraesthesia and lymphoedema. The various methods described in the literature identify the sentinel lymph nodes in approximately 96 % of cases and associated with a false negativity rate of 5 to 10 %. Afalse negative sentinel nodeis defined as the proportion of cases in whom sentinel node biopsy is reported as negative, but therest of axillary lymph node(s)harbours cancer cells. The possible causes of a false negative sentinel lymph node may be because of blocked lymphatics either by cancer cells or following fibrosis of previous surgery/radiotherapy, and an alternative pathway opens draining the blue dye or isotope to anotheruninvolved node. The other reasons may be two lymphatic pathways for a tumour area, the one opening to a superficial node and the other in deep nodes. Sometimes, lymphatics do not relay into a node but traverse it going to a higher node. In some patients, the microscopic focus of metastasis inside a lymph node is so small-micrometastasis (i.e. between 0.2 and 2 mm) or isolated tumour cells (i.e. less than 0.2 mm) that is missed by the pathologist. The purpose of this review is to clear some fears lurking in the mind of most surgeons about the false negative sentinel lymph node (FNSLN).
authors.affiliation: Department of Surgical Disciplines, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029 India.
authors.forename: Kamal
authors.initials: K
authors.lastname: Kataria
authors.affiliation: Department of Surgical Disciplines, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029 India.
authors.forename: Anurag
authors.initials: A
authors.lastname: Srivastava
authors.affiliation: Department of Surgical Disciplines, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029 India.
authors.forename: Darakhshan
authors.initials: D
authors.lastname: Qaiser
keywords: Clinically overt; False negative; Micrometastasis; Sentinel lymph node biopsy; Tumour emboli