Lymph node revealing solution: a new useful method for isolation of minute axillary lymph nodes in breast cancer

ABSTRACT

Breast cancer is one of the most common malignancies in the world. The most important prognostic factor in this cancer is the stage of the tumor. Detection of lymph nodes with or without malignancy is essential for determining the stage of the tumor and setting a therapeutic plan. There are different methods for isolating lymph nodes in surgical specimens of breast cancer in the pathology department. The most popular method is routine palpation, but isolation of very small lymph nodes is difficult and time consuming and some may be missed. The main goal of this paper is to describe a new, precise and easy technique for finding nodes in breast cancer specimens. In this study 50 cases of breast cancer were randomly selected. In these cases axillary fat was examined for lymph nodes by traditional method, and then the entire axillary fat was immersed overnight in a lymph node revealing solution [LNRS] composed of various traditional fixatives and fat solvent. After overnight fixation the lymph nodes stood out as white chalky nodules on the background of yellow fat. They were then excised, processed and stained by routine Hand E method. The total number of lymph nodes found by traditional method in these 50 cases was 660. After application of LNRS, 178 additional lymph nodes measuring from 0.5 to 9 mm were found. The LNRS increased the mean number of nodes per case from 13.20 +/- 6.61 found by traditional method to 16.67 +/- 7.64 nodes per case [p value<0.01]. The size of lymph nodes identified by LNRS was significantly smaller than those found by traditional method [p value<0.01]. In 8 cases, tumor stage was increased by application of LNRS in addition to routine palpation. As a whole LNRS is a useful, rapid and good fixative. It significantly enhances the yield of lymph nodes in the axillary fat of breast cancer specimens