Which ocular finding should prompt a referral for a colonoscopy to rule out colon cancer?

Familial Adenomatous Polyposis (FAP) is a hereditary condition characterized by the development of numerous polyps in the colon, which have a high risk of progressing to colorectal cancer if not properly managed. Patients with FAP also exhibit specific ocular findings, such as iris Lisch nodules. These nodules are associated with neurofibromatosis type 1 but can also occur in FAP.

In the context of this question, the presence of FAP is significant. If an individual exhibits ocular signs consistent with FAP or has a family history of this condition, it signifies a need for increased surveillance for colorectal cancer, traditionally through colonoscopy, due to the elevated cancer risk associated with this genetic disorder. This proactive measure aims to detect malignancies early, significantly improving outcomes.

Understanding the connection between FAP and colon cancer risk illustrates the importance of referral for a colonoscopy when relevant ocular findings suggest this condition.