Universal application of colonoscopy mitigates unnecessary laparotomy in patients with pelvic tumors of unknown origin

Objective: The purpose of this study was to establish the utility of universal colonoscopy in patients with giant pelvic masses of unknown origin. Design: The study was designed as a retrospective case review. Materials and Methods: Patients who underwent laparotomy for pelvic tumors of unknown origin with a discharge diagnosis of colorectal cancer were identified. Records were reviewed to determine whether sufficient data had been present preoperatively or if further evaluation would have established a definitive preoperative diagnosis. Results: Over an 8-year period, 10 patients were originally thought to have gynecologic cancer and later found to have colorectal cancer. Three patients had had preoperative endoscopy: one negative, one misinterpreted by the pathologist, and one misinterpreted by the gastroenterologist. The 7 remaining patients had had mucosal abnormalities in their gross surgical specimens, suggesting that colonoscopy would have been diagnostic. Five patients had seven additional procedures to treat their colorectal cancer after the initial procedure. Conclusions: CT scan alone is insufficient to rule out colorectal cancer in patients with pelvic masses presumed to be gynecologic in origin. Universal application of colonoscopy in these patients may improve preoperative diagnostic yield in as many as 70% of patients and reduce unnecessary procedures in up to 50%.