Adenomas with Adenocarcinoma: A Study Evaluating the Risk Of Residual Cancer And Lymph Node Metastasis

Abstract

Background and Aims: The increasing number of cases with colorectal adenomas with adenocarcinoma necessitates renewed evaluation of classification systems and risk factors. The aim for this retrospective study was to evaluate the potential risk of residual cancer and lymph node metastasis in patients with colorectal adenomas with adenocarcinoma. Material and Methods: An investigation of adenomas with adenocarcinoma in 74 patients was performed on histological slides and compared with clinical characteristics. A total of 44 of the samples were from macroscopically and microscopically completely resected lesions, and cancer at extended surgery was compared with pathology reports, classifications, and histopathological features. Results: In all, 26 cases of adenomas with adenocarcinoma in the rectum and rectosigmoid were among women and 11 in men while 22 men as opposed to 15 women had primary lesions in colon, giving a significant association between gender and localization ( p = 0.01). For macroscopically and microscopically fully resected lesions, Haggitt classification or submucosal invasion did not correlate with cancer at extended surgery. The lack of information on resection margins in the primary pathology reports was found to correlate significantly with residual cancer at extended surgery ( p < 0.001) with residual cancer in 3 out of the 10 cases with no information, 1 out of the 5 where the resection margins were uncertain, 1 out of the 4 where the resection margins were not free, and none of the 25 cases when the resection margins were reported as free. In colon, 1 case out of the 6 with extended surgery (16.7%) was diagnosed with residual cancer compared with 4 out of the 10 (40%) from rectum. Conclusions: Haggitt or submucosal classifications were not found to be predictors for residual cancer in the remaining bowel tissue or lymph node metastasis. The only significant factor indicating increased risk of residual cancer was the lack of information on resection margins in the pathology report. Surgeons should therefore be alert when adenomas with adenocarcinomas are not confirmed as microscopically free in the pathology report.