Introduction: Hereditary nonpolyposis colorectal cancer (HNPCC), also known as Lynch syndrome, represents 5% to 7% of colorectal cancers. It is an autosomal dominant inherited disorder characterized by an early onset of colorectal tumors, predominantly proximal, and multiple and microsatellite instability. We used the Amsterdam II criteria for its identification.
Objective: To analyze the case of a patient with a family history of malignant colorectal tumors at an early age of onset.
Case report: A 40-year-old woman, from Valle de Punilla, Cordoba, Argentina, with no previous medical history, complained of mild changes in her bowel habits and was admitted to the general surgery department with the radiographic diagnosis of a tumor in the hepatic flexure of the colon. She underwent a right hemicolectomy for a Dukes B stenosing tumor (T3N0M0, stage IIa).
Conclusion: In this report, we present the case of a woman with HNPCC who met the Amsterdam II criteria II. Family members who meet these criteria should be screened for the mutation in MMR genes. As genetic tests are not routinely available, an annual colonoscopic surveillance of all asymptomatic relatives older than 25 to 30 years old who meet the criteria is recommended, regardless of the availability and/or the outcome of genetic testing.