PURPOSE:We describe a patient who had precancerous colonic symptoms and a positive family history of multiple occurrences of early‐onset colorectal cancer in her first‐degree and second‐degree relatives consistent with hereditary nonpolyposis colorectal cancer. Hereditary nonpolyposis colorectal cancer diagnosis had not been made before her diagnosis of carcinoma of the cecum with liver metastasis. She died at age 20, leading to litigation. Controversies about standards of care, their malpractice implications, and pertinent legal issues are discussed.METHODS:Review of the medical and family history was made by the expert witness (HTL) with appropriate documentation of the chronology of symptoms, as derived from depositions. These documents revealed that the patient's mother had repeatedly discussed with the caregivers her concern about the family history of colon cancer and the need for appropriate surveillance.RESULTS:The patient's colonic symptoms progressed for a period of three years. Flexible sigmoidoscopy was performed by a nonphysician. The physician who ordered the procedure considered this appropriate because isolated polyps were reported in the patient's father and paternal uncle, which apparently led him to believe that the diagnosis was familial adenomatous polyposis. During litigation procedures, a pedigree was constructed and found to be consistent with hereditary nonpolyposis colorectal cancer. The case was settled in favor of the plaintiff before trial.CONCLUSION:It is essential to understand the natural history of hereditary nonpolyposis colorectal cancer, inclusive of the need for surveillance colonoscopy in patients at increased risk by virtue of their position in their family pedigree.