Abstract
Familial adenomatous polyposis (FAP) is an inheritable disease which characterize by the development of numerous polyps in the colon and rectum. This usually occurs at about the second decade of life and the polyps are likely to develope to cancer with 100% incidence unless treated. Among the several surgical options available, one of the most difficult decisions is determing whether the anal transitional mucosa (ATM) should be retained or completely removed. The risk of developing cancer is less when the mucosa is completely removed, however post-operative anal functionality seems to be better in ATM retaining operations. This is especially noted when operating on early-detection cases in which the polyp had not fully developed. This presents a dilemma in which it is difficult to determine the operative procedures. In an attempt to classify the cancer risk of the background rectal mucosa, we observed the microadenoma in the resected specimens by the utilizing the stereomacroscope, magnifying endoscope, and finally, the videomacroscope which was developed by this research team. Microadenomas, and even single gland adenomas can be observed by these instruments. Microadenomas were histologically corroborated after observation with the stereomacroscope. FAP is characterised by density of polypes as follows. 1. carpet type 2. scattered type. In the latter type, microadenoma are scarcely present in the ATM. Cancer risk seems to be lower in this type of FAP. Therefore, an operative procedure for FAP should be chosen by taking into account the reduced cancer risk with a complete removal of high risk mucosa and the patient's quality of life (QOL) with the resulting post operative anal function by an ATM retaining prosedure. A videomacroscope is very useful instrument for this diagnostic purpose.
