The Role of Imaging Exams in the Axillary Staging

Abstract

INTRODUCTION: Axillary status is an important prognostic factor, and helpful in adjuvant treatment selection for breast cancer patients. Historically, lymphadenectomy is part of surgical treatment for breast cancer, both for regional therapeutics and for cancer staging. However, this method has been associated with undesirable side effects. The use of sentinel lymph node biopsy was created in order to minimize these effects, with results analogous to those of lymphadenectomy. Imaging exams may assist in the presurgical detection of metastases for axillary lymph nodes, which present alterations in size or morphology. The method’s accuracy is increased when associated with a percutaneous biopsy in highly or moderately suspicious lymph nodes. Ultrasonographic evaluation of the axilla has also been routinely performed to ascertain the presence of axillary metastases in the preoperative stage, and to reduce the need for a new surgery if they are considered positive. MATERIALS AND METHODS: Twenty patients in different stages of breast cancer and who presented lymph nodes of intermediary or high suspicion based on axillary ultrasound were selected. Alterations such as cortical thickening, smaller or absent hilum, and/or changes in vascular shape or pattern are considered suspicious. Fine-needle aspirations (FNA) of these lymph nodes were performed guided by the sonogram, cytological analysis was compared to the anatomopathological analysis of the surgical sample from the axilla, and the method’s accuracy was verified. RESULTS: Axillary metastases were histologically confirmed in 13 patients (13/20; 65%) and ruled out in 6 patients (6/20; 30%); a false positive and no false negative were obtained with the cytology. The positive predictive value was of 93%, and the negative, of 100%. DISCUSSION: Ultrasonography is a sensitive method for the detection of metastatic disease in axillary lymph nodes, yet in some cases the disease is present in lymph nodes with normal characteristics, or in hyperplastic lymph nodes. FNA in suspicious lymph nodes renders the diagnosis more specific, and changes the surgical approach for the patient. When metastasis is diagnosed during the preoperational stage, sentinel lymph node search may be waived, resulting in faster surgical intervention and in proceeding directly to axillary emptying or to neoadjuvant chemotherapy. CONCLUSION: Axillary staging performed by ultrasound, combined with percutaneous biopsy, may decrease the need for additional surgical procedures, allow for better surgical strategy, and provide greater rapidity to treatment. Alterations in size and morphology of axillary lymph nodes are predictive of metastatic disease, and cytological or histological evaluation are recommended when such alterations are present. At our institution, axillary ultrasonography is routinely performed and, when recommended, percutaneous biopsies are performed, with preference given to FNA.