system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 24-year-old man comes to the physician because of 2 episodes of bleeding from the rectum over the past month. The patient’s father died of colon cancer at the age of 42. The patient has no history of any serious illness and takes no medications. He does not smoke. His vital signs are within normal limits. Physical examination shows a small hard mass over the right mandible that is nontender and fixed to the underlying bone. A similarly hard and painless 5 × 5 mass is palpated over the rectus abdominis muscle. On examination of the rectum, a polypoid mass is palpated at fingertip. Proctosigmoidoscopy shows numerous polyps. Which of the following best explains these findings?
assistant
Gardner’s syndrome