Aberrant drainage of sentinel lymph nodes in colon cancer and its impact on staging and extent of operation

BackgroundThe role of aberrant lymphatic drainage in changing operations for patients undergoing sentinel lymph node mapping in colon cancer has not been described on a large scale.MethodsPatients with colon cancer underwent sentinel lymph node mapping and standard oncologic resection. Aberrant lymphatic drainage was identified outside the standard resection margin, requiring change of the extent of operation. Objectives were to identify the frequency of aberrant lymphatic drainage leading to changes of operation and staging.ResultsAmong 192 patients undergoing standard oncologic resection, 42 (22%) had extended surgery because of aberrant lymphatic drainage. Nodal positivity was higher in patients undergoing change of operation, at 62% compared with 43% of those undergoing only standard oncologic resection. In 19 of 192 patients (10%), positive sentinel nodes were found in aberrant locations.ConclusionsSentinel node mapping in patients with colon cancer detects aberrant drainage in 22% of patients, changing the extent of operation.