The objective of this trial is to define the rate of upstaging of colon carcinoma lymph node metastasis with sentinel lymph node (SLN) mapping.

Null hypothesis: There is no difference in the rate of lymph node metastasis between conventional histopathological processing of lymph nodes and SLN mapping with detailed pathologic examination using immunohistochemistry (IHC) in patients undergoing resection of colon carcinoma.

Inclusion Criteria:

1. 18 years of age
2. Primary, non-metastatic [Stage I, II (localized, node negative), or III (localized, node positive)] colon carcinoma confirmed by tissue biopsy or colon mass clinically consistent with cancer and eventually confirmed by pathology
3. Palpable mass at time of surgery
4. Capable of providing informed consent

Exclusion Criteria:

1. Prior radiation or chemotherapy
2. Non-palpable colon tumor
3. Recurrent or Stage IV (metastatic) colon cancer
4. Unable to give informed consent

Up to 150 male or female military healthcare beneficiaries over the age of 18 years presenting at the Walter Reed Army Medical Center (WRAMC) General Surgery clinic with the diagnosis of biopsy-proven, primary, non-metastatic (Clinical Stage I,II or III) colon carcinoma will be enrolled. Subjects with colonic masses clinically consistent with colon cancer, and eventually confirmed by pathology, will also be enrolled.