Cima, Robert

AbstractThe Rochester Epidemiology Project (REP), a longitudinal population-based database, is the largest epidemiologic database in the world. Originally established at Mayo Clinic in Rochester, Minnesota, the REP has been instrumental in defining the natural history of disease states and the impact of treatment in a well-defined population. In the United States, the REP has made important contributions to the colon and rectal literature, largely because healthcare is fragmented with no unique identifier to longitudinally follow-up with a patient throughout the system over his or her lifespan. Investigation with the REP has provided insight to the economic burden associated with inflammatory bowel disease, the benefit of screening for colorectal cancer, and the natural history of Mekel's and diverticular disease. In addition to practice changing research, the REP can be used as a model for future linkage systems in the United States.

Background Meckel's diverticulum is present in about 2% of the population. The literature reports 3.2% incidence of tumors within Meckel's diverticulum; the tumors are predominantly benign. Objective and methods The purpose of this study was to evaluate malignant tumors in Meckel's diverticulum through systematic review of the literature and review of electronic medical records including pathology reports over 14 years at the Mayo Clinic, Rochester, USA. Results A literature review over the last 10 years identified 37 citations with 402 patients (median age: 58 years; 68.9% males). The predominant malignancy reported was neuroendocrine tumor 84.6%, followed by gastrointestinal stromal tumor 8.2%, and adenocarcinoma 6%. At the time of diagnosis, 29.5% of patients had metastases. In the Mayo Clinic electronic medical records review, there were 19 patients (5.1% of them surgically removed Meckel's diverticulum) who had a malignancy associated with Meckel's diverticulum: 63.2% neuroendocrine tumor, 10.5% gastrointestinal stromal tumor, 5.3% adenocarcinoma, 5.3% pancreatic epithelial neoplasia, and 15.8% metastases from secondary location. Median size of the malignancy was 7 mm, and 17/19 malignancies were coincidental findings. Most neuroendocrine tumors infiltrated the submucosa, while gastrointestinal stromal tumor and adenocarcinoma invaded the serosa. At the time of diagnosis, 33.3% of patients had metastases. Conclusion About 5% of Meckel's diverticulums resected were associated with malignant tumors, most commonly neuroendocrine tumor, and a significant portion of Meckel's diverticulum malignancy was metastatic at the time of discovery.