Can additional histopathological examination of ultrasound-guided axillary lymph node core biopsies improve preoperative diagnosis of primary breast cancer nodal metastasis?

To assess whether an additional histopathological examination of ultrasound-guided core biopsy (USCB)/fine-needle aspiration (FNA) of abnormal axillary lymph nodes (ALN) can improve the preoperative diagnosis of axillary nodal metastasis.Women with suspected invasive breast cancer and abnormal axillary ultrasound (AUS), but negative USCB on standard histopathological assessment were included. From the core biopsies six additional levels were sectioned for haematoxylin and eosin examination, and two levels were sectioned for immunohistochemistry with AE1/3. The presence of metastatic disease was noted.The USCB of 102 patients were submitted for additional histopathological examination, of whom 58 had screen-detected lesions and 44 had symptomatic lesions. Eighty underwent axillary surgery for invasive carcinoma (n = 74) or for ductal carcinoma in situ (DCIS) requiring mastectomy (n = 6). Twelve patients were found to have nodal disease with a mean of two nodes involved. The additional histopathological assessment of the nodal USCBs revealed tumour not seen at the standard examination in only three cases, which consisted of isolated tumour cells (n = 2) and micrometastasis (n = 1). All three patients underwent subsequent axillary node clearance; however, no upgrade of axillary disease was found at final histopathology.Additional histopathological examination of USCBs of radiologically abnormal ALN does not improve the preoperative diagnosis of axillary nodal metastasis in primary breast cancer and may lead to unnecessary axillary clearance.