Pathological axillary lymph nodes detected at mammographic screening

AIM: To investigate the significance of abnormal axillary lymph nodes detected at mammographic screening in the absence of a concomitant breast lesion. METHODS: Twenty-three thousand, seven hundred and seven women were screened at the Merrion Unit as part of the Irish National Breast Screening Programme ('BreastCheck') in the period June 2000 to July 2002. Nine women (0.4 per 1000 women screened) were found to have an abnormal axillary lymph node(s) in the absence of a mammographic breast lesion and were recalled for assessment. The radiological criteria for recall included: size greater than or equal to 15 mm, round or irregular shape, increased node density and absence of hilar lucency. Each woman underwent further mammographic views, ultrasound examination of axilla and breast, clinical examination and lymph node biopsy either by 14 G needle core biopsy (NCB) or open excision. RESULTS: The final pathological diagnoses in the nine patients were oestrogen receptor (OR) positive metastatic breast carcinoma (two patients), metastatic malignant melanoma (one patient), malignant lymphoma (two patients), caseating granulomatous lymphadenitis suggestive of tuberculosis (one patient), and other benign conditions (three patients). CONCLUSION: Abnormal axillary lymph nodes, in the absence of an accompanying breast lesion, are rarely identified on screening mammogram, but may harbour significant pathology and their presence on screening mammogram merits further investigation including biopsy