Significant deposition of wild type transthyretin-derived amyloid in the gastrointestinal tract of aged individuals.

Two male patients aged 72 and 77 were found to have transthyretin (TTR) immunoreactive amyloid deposits in their gastrointestinal tracts when they underwent surgery for gastric and sigmoid colon cancer, respectively. They had no cardiac symptoms and there was no mutation in their TTR gene. Amyloid deposits were seen mainly on vascular walls in submucosal layers of the stomach and colon, while the muscularis mucosae, which is invariably affected in familial amyloid polyneuropathy (FAP), was completely free of amyloid deposition. The pattern of TTR-derived amyloid deposition in the gastrointestinal tract in SSA and in FAP are quite different.