FAP : Gross Pathology
Gross Pathology of Familial Adenomatous Polyposis (FAP): Colectomy specimens show 1000 or more macroscopic lesions in average cases. Most polyps are smaller than 1 cm in size. APC gene mutations between codons 1250 and 1464 (especially around codon 1300) are associated with more profuse polyp formation (similar to the case shown here). Mutations near the extreme 5' and 3' ends of the APC gene produce fewer polyps and cause attenuated FAP. About 25% of FAP patients have cancer at the time of colectomy.
Image courtesy of Dr. Jean-Christophe Fournet, Paris, France; humpath.com; Used with permission