OUTLINE: Patients undergo preoperative endoscopy with injection of technetium Tc 99m sulfur colloid around tumor followed by celiotomy and intraabdominal exploration. At 30 minutes following injection, patients undergo lymphatic mapping with a gamma probe and biopsy of the sentinel lymph node(s). Following biopsy and mapping, patients undergo resection of primary tumor. Patients are followed postoperatively, every 4-6 months for 2 years, every 6 months for 1 year, and then annually thereafter.