Gardner syndrome is a old term. It was used to describe families with polyps or colon cancer who also had skin problems.
It's named after doctor Eldon John Gardner who publish a paper in the American Journal of Human Genetics in 1951 describing a family with multiple bowel polyps (adenoma) and osteofibromas.
It is no longer used as it describes the clinical features of 2 hereditary cancer syndromes that have very different genetic causes and different cancer risks: Lynch syndrome and Familial Adenomatous Polyposis syndrome.
In Lynch syndrome the skin lesions are sebaceous adenocarcinomas of the skin and there is also a high risk of colon (bowel), uterine, ovarian and other digestive tract cancers.
By contrast, in Familial Adenomatous Polyposis syndrome individuals present with skin lumps such as epidermoid cysts or lipomas, desmoids (tumour of the connective tissues) and osteomas (benign bone growths, often found in the jaw). In this syndrome, hundreds or even thousands of polyps may occur in the bowel from a very young age and the lifetime risk of colon cancer is 100% if nothing is done to reduce the risk.Read more about Lynch syndrome and Familial Adenomatous Polyposis syndrome