This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
Lynch syndrome is seen in? 
Select and explain. 
A. Hereditary non polyposis colon cancer, B. Gastric adenocarcinoma, C. Hepatoma, D. Familial polyposis of the colon
A: Hereditary non polyposis colon cancer
Answer: A: Hereditary non polyposis colon cancer 
Explanation: Hereditary non polyposis colon cancer Hereditary nonpolyposis colon cancer (HNPCC), also known as Lynch syndrome, is another autosomal dominant trait. It is characterized by the presence of three or more relatives with histologically documented colorectal cancer, one of whom is a first-degree relative of the other two; one or more cases of colorectal cancer diagnosed before age 50 in the family; and colorectal cancer involving at least two generations.