Suspicious axillary lymph nodes in patients with unremarkable imaging of the breast

The aim of this study was to evaluate the pathological findings and the method of tissue harvesting in those patients who have both suspicious axillary lymph nodes and normal imaging of the breast.

From January 2005 to June 2008 all female patients who underwent opportunistic screening mammography and ultrasound examination of the breast and the axilla, and who were found to have suspicious axillary lymph nodes seen on ultrasound examination, were retrospectively analysed. Tissue harvesting was done by fine needle aspiration, core needle biopsy, or open biopsy.

Out of approximately 7500 screened patients, 51 were found to have suspicious axillary lymph nodes on ultrasound with unremarkable breast ultrasound and mammography. Histopathology and/or cytology of these lymph nodes showed 33 benign and 18 malignant results. Of the malignant results only 1 case was an occult invasive lobular breast carcinoma detected afterwards on breast magnetic resonance imaging. Eleven cases were non-Hodgkin lymphomas, 4 were malignant melanomas, and 2 were metastases from the lower genital tract. Diffuse cortical thickening and complete loss of echo texture were the only features on ultrasound predicting malignancy. Palpation and mean size of the evaluated lymph nodes had no predictive value for malignancy. In the 33 cases of non-malignant pathology 9 patients showed patterns of specific infectious disease, including 4 patients with tuberculosis.

Suspicious lymph nodes of the axilla seen on ultrasound rarely indicate occult breast cancer but show a variety of other malignancies and generalised infectious disease requiring further treatment. Fine needle aspiration and/or core needle biopsy are both sufficient methods for clarification in the majority of cases.