Sentinel lymph node study in colorectal cancer using serial sectioning and Hematoxylin-Eosin staining: importance and limitations.

The lymph node involvement represents an important predictor for survival in colorectal cancer; consequently, the best pathologic evaluation is necessary in order to adequately assess the lymph node status. This study aims to evaluate the impact of sentinel lymph node technique in colorectal cancer in lymphatic basin staging. The study included 43 consecutive operated cases, in which the identification of sentinel lymph node was performed during surgery (in vivo procedure - colon cancer) or immediately after the removal of the resection specimen (ex vivo procedure - rectal cancer). These cases were matched with 45 control cases. The identified sentinel lymph node was separately examined using multiple sections and Hematoxylin-Eosin staining method. The detection rate, accuracy, sensitivity and false negative rate were better for colon cancer (86.36%; 84.21%; 66.66%; 23.07%) vs. rectal cancer (61.9%; 84.61%; 50%; 18.18%), but there are no arguments for the feasibility of the technique in every day practice. Further studies and methods are mandatory in order to improve the staging of the pN status in colon and rectal cancer.