Christine Westra BS, Abstract Co-Author: Nothing to Disclose

Vandana Mukesh Dialani MD, Abstract Co-Author: Nothing to Disclose

Shambhavi Venkataraman MD, Abstract Co-Author: Nothing to Disclose

Valerie J. Fein-Zachary MD, Abstract Co-Author: Nothing to Disclose

Alexander Brook PhD, Abstract Co-Author: Spouse, Research Grant, Guerbet SA

Tejas S. Mehta MD, MPH, Presenter: Nothing to Disclose

To evaluate prevalence and identify features predictive of malignancy in imaging-detected lymph nodes (LNs) in women without concurrent cancer.

Retrospective review of all image-guided LN fine needle aspirations (FNA) and core needle biopsies (CNB) from 1/1/08-12/31/10. LNs in patients without concurrent cancer comprised our study group (SG; n=80) and with concurrent breast cancer our control group (CG; n=66). FNAs were sent for flow cytometry in addition to cytology at discretion of breast imager. Blinded to cytology/histology, imaging features of LNs including size, loss of fatty hilum, and/or focal/diffuse cortical thickness were recorded. BI-RADS category was assigned by reviewer based on LN appearance.

In 80 SG cases, 63 (78%) had FNA and 17 (22%) had CNB; all in CG had FNA. Of the 80 SG cases, 69 (86%) were negative, 2 (3%) positive, 6 (7%) atypical and 3 (4%) non-diagnostic (ND). Of 8 atypical/positive LNs, 3 had breast cancer, 2 had lymphoma, and 3 negative on excision. Of 66 CG cases, 30 (45%) were negative, 30 (45%) positive, 5 (8%) atypical and 1 (2%) ND. There were 6 false negative FNAs in CG; all atypical/positive LNs in CG were positive for breast cancer on excision. ND LNs were negative on follow up/excision in both groups. Prevalence of malignancy in LNs in SG was 6% (5/80) and in CG 62% (41/66; p<0.0001). Positive LNs were larger than negative LNs for both groups (p<0.0001). Loss of fatty hilum in SG had 100% sensitivity and NPV, 74% specificity and 21% PPV for cancer, compared to CG with 30% sensitivity, 47% NPV, 96% specificity, and 92% PPV. In SG LNs with fatty hilum present, cortical thickness of >= 3mm and/or eccentric/focal cortical thickening were negative and not predictive of malignancy. If BI-RADS 4C/5 were used as threshold to biopsy, the sensitivity, specificity, PPV, and NPV for cancer in SG would have been 100%, 99%, 83% and 100% respectively, higher than CG results of 73%, 92%, 93% and 68% respectively.

In the absence of concurrent breast cancer, using loss of fatty hilum as criterion to biopsy image-detected LNs keeps sensitivity of 100% but lowers false positives. FNAs should also be sent for flow cytometry to diagnose lymphoma.

Without concurrent breast cancer, loss of fatty hilum as criterion to biopsy LNs has 100% sensitivity with low false positives. Flow cytometry is also needed in these patients to exclude lymphoma.

Westra, C, Dialani, V, Venkataraman, S, Fein-Zachary, V, Brook, A, Mehta, T, Indications for Biopsy of Imaging-detected Intramammary and Axillary Lymph Nodes in the Absence of Concurrent Breast Cancer.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13015708.html