IMPLICATIONS/DISCUSSION: The majority of studies have shown a two-to four-fold increase in the incidence of colon cancer in patients with similarly afflicted first-degree relatives. Screening for colon cancer with a positive history in a first-degree relative is advised ten years prior to the index case. Hereditary nonpolyposis colon cancer (HNPCC) is a consideration in this patient. The genetic basis for HNPCC is heterogeneous involving chromosomes 2, 3, and 7. With the multiple genetic focus of HNPCC, genetic testing is seldom employed. The family is clinically positive for HNPCC as there are more than two cases of colon cancer spanning at least two generations. HNPCC is caused by defective DNA mismatch repair genes. Afflicted patients develop polyps at a rate similar to the normal population. However, because of genetic defects, precursor adenoma lesions undergo a more rapid progression to carcinomas than usual adenomas. HNPCC typically presents during the fourth and fifth decades of life. Affected patients are predisposed to a higher frequency of proximal colonic lesions with more advanced pathology, as seen in this case.