[How to optimize lymph node dissection in colorectal cancers. A technique for simple and efficacious clarification]

Studies relating to the prognosis of colorectal carcinomas insist on the quality of mesocolic examination and on the frequency of metastases in minute lymph nodes. The aim of our study was to evaluate an easy, rapid and new clearance method recently described by Koren et al. Twenty-one surgical specimens for colorectal carcinomas have been investigated. After lymph node examination with the traditional method, the mesocolic fat was immersed in a clearing solution. After 6 hours, lymph nodes stood out as white chalky nodules, and were dissected. By the traditional method 182 lymph nodes were detected and 89 additional lymph nodes after clearing. In one case, the detection of a metastasis in lymph node after clearing allowed to upstage the tumour from Dukes B (N0) to Dukes C (N+). This easy and inexpensive method allows the detection of minute lymph nodes and helps to establish a more accurate staging.