[188] Ultrasound-Guided Needle Core Biopsy of the Axilla Often Samples Sentinel Node

TT Ha, A Contreras, HA Sattar. University of Chicago, Chicago, IL

Background: Axillary lymph node status is an important prognostic factor in the assessment of breast cancer patients. Sentinel lymph node biopsy is the standard of care for screening clinically-node negative patients. More recently, axillary ultrasound has proven to be a valuable technique for screening the axilla. At our institution, a negative biopsy is followed up with a sentinel node biopsy to ensure adequate screening of the axilla. Our study aims to determine how often a negative ultrasound guided lymph node biopsy samples sentinel lymph node.
Design: 54 patients with negative axillary lymph node biopsies were identified from the University of Chicago Pathology archives (2005 - 2008). Sentinel node excision, along with non-sentinel nodes when available, were reviewed to determine which nodes exhibited biopsy site changes.
Results: All 54 patients with negative ultrasound-guided needle core biopsy underwent sentinel node biopsy (average 3 nodes removed; range 1-10) and 22 had additional non-sentinel nodes excised (average 1, range 1-3) in the vicinity of the sentinel node (taken due to accessibility at the time of biopsy). Eight of the 54 patient had a positive sentinel node on frozen section resulting in complete axillary dissection (average 16 additional nodes recovered). Changes consistent with prior ultrasound biopsy were found in a sentinel node in 25 patients (46% of all cases reviewed); in a non-sentinel node in 5 patients (9%) and in a node present in axillary dissection in 3 patients (6%). In 21 cases, a prior biopsy site was not identified and was presumed to be left behind in the remaining axillary nodes in the patient. When present, the biopsy site exhibited features consistent with the time elapsed since the ultrasound-guided procedure. Interestingly, of the eight positive sentinel nodes on frozen section, four exhibited biopsy site changes that were away from the focus of metastatic carcinoma.
Conclusions: Negative ultrasound-guided needle core biopsy often samples one of the sentinel nodes (46% of cases). The particular node with which biopsy site change is related should be noted in pathology reports. This vital information will help radiologists further refine biopsy thresholds and criteria.
Category: Breast

Tuesday, March 10, 2009 9:30 AM

Poster Session III # 72, Tuesday Morning