Purpose: Endoscopically unresectable apparently benign colorectal polyps are considered by some surgeons as ideal for their early laparoscopic colectomy experience. Our hypotheses were: (1) a substantial fraction of patients undergoing laparoscopic colectomy for apparently benign colorectal neoplasia will have adenocarcinoma on final pathology; and (2) in our practice, we perform an adequate laparoscopic oncological resection for apparently benign polyps as evidenced by margin status and nodal retrieval.
Methods: Data from a consecutive series of patients undergoing laparoscopic colectomy (on an intention-to-treat basis) for endoscopically unresectable neoplasms with benign preoperative histology were retrieved from a prospective database and supplemented by chart review.
Results: The study population consisted of 63 patients (mean age 67, mean body mass index 29). Two out of 63 cases (3%) were converted to laparotomy because of extensive adhesions (n = 1) and equipment failure (n = 1). Colectomy type: right/transverse (n = 49, 78%); left/anterior resection (n = 10, 16%); subtotal (n = 4, 6%). Invasive adenocarcinoma was found on histological analysis of the colectomy specimen in 14 out of 63 cases (22%), standard error of the proportion 0.052. Staging of the 14 cancers were I (n = 6, 43%), II (n = 3, 21%), III ( = 4, 29%), and IV (n = 1, 7%). The median nodal harvest was 12 and all resection margins were free of neoplasm. Neither dysplasia on endoscopic biopsy nor lesion diameter was predictive of adenocarcinoma. Eight out of 23 (35%) patients with dysplasia on endoscopic biopsy had adenocarcinoma on final pathology versus 6/40 (15%) with no dysplasia (p = 0.114, Fisher's exact test). Mean diameter of benign tumors was 3.2 cm (range 0.5-10.0cm) versus 3.9cm (range 1.5-7.5cm) for adenocarcinomas (p = 0.189, t - test).
Conclusion: A substantial fraction of endoscopically unresectable colorectal neoplasms with benign histology on initial biopsy will harbor invasive adenocarcinoma, some of advanced stage. This finding supports the practice of performing oncological resection for all patients with endoscopically unresectable neoplasms of the colorectum. The inexperienced laparoscopic colectomist should approach these cases with caution.