RATIONALE: Diagnostic procedures, such as lymphography, may improve the identification of patients with metastatic colorectal cancer.

PURPOSE: Clinical trial to study the effectiveness of lymphography in determining the presence or absence of metastatic colorectal cancer in patients.

OBJECTIVES: I. Confirm that injection of isosulfan blue into the mucosa or serosa immediately adjacent to a colorectal cancer results in the lymphatic transport of that agent initially to a specific regional lymph node that can readily be identified on visual inspection, dissected, and histologically evaluated for the presence or absence of metastatic disease.

OUTLINE: All patients receive an injection of isosulfan blue into peritumor serosa upon intraoperative identification of the primary tumor, prior to mesenteric mobilization. If colonoscopy is otherwise indicated, the injection may be delivered to the peritumor mucosa via colonoscopy during the case. The mesentery adjacent to the injection is inspected and the lymphatic pattern and nodes demonstrated by the isosulfan blue are diagrammed and photographed. The sentinel node(s) are surgically dissected and evaluated. If needed, a second injection of isosulfan blue may be given. Prior to mobilization of liver for resection of metastases, isosulfan blue is injected subcapsularly around the metastatic lesion.

PROJECTED ACCRUAL: There will be 10 patients accrued into this study.

DISEASE CHARACTERISTICS: Patients must be undergoing surgical resection of a colorectal primary adenocarcinoma Metastatic colorectal cancer to liver (hepatic metastases) allowed

PATIENT CHARACTERISTICS: Age: 18 to 75 Performance status: Not specified Life expectancy: Not specified Hematopoietic: Not specified Hepatic: Not specified Renal: Not specified Other: No known or suspected allergy to isosulfan blue Not pregnant

PRIOR CONCURRENT THERAPY: See Disease Characteristics