Case: AP93
Contributor's Comment: The section was sampled from a right hemicolectomy, which also included a 5 cm segment of small bowel that was adherent to, and contained a perforated colonic ulcer. Prior to the right hemicolectomy, a colonoscopy was performed for GI bleeding, and the biopsy recognized the ulcer but not the cause of ulceration. Apart from the 3 cm deep colonic ulcer, the remainder of the colonic mucosa was grossly normal. Amyloidosis of the vessels was confirmed by a positive Congo Red stain, but immunohistochemistry typing of the amyloid was not performed. However, CMV immunoreactivity was negative. This 69-year-old woman was on maintenance hemodialysis for over a year when GI bleeding and obstructive symptoms occurred. The cause of chronic renal failure is unknown, and renal biopsy was not performed as the patient already had contracted kidneys at presentation. From the history, amyloidosis of the colonic vessels is probably related to beta-2 microglobulin associated with chronic renal failure or maintenace hemodialysis. While amyloidosis represents the cause of ulceration or GI bleeding, the mechanisms leading to such complications may be complex (1-4).


1. Koppelman RN, Stollman NH, Baigorri F, Rogers AI. Acute small bowel pseudo-obstruction due to AL amyloidosis: a case report and literature review. Am J Gastroenterol 95:294-296, 2000
2. Bruno MJ, van Dorp WT, Ferwerda J, Dekker W, Schut NH. Colonic pseudo-obstruction due to beta-2-microglobulin amyloidosis after long-term haemodialysis. Eur J Gastroenterol Hepatol 10:717-720, 1998
3. Jimenez RE, Price DA, Pinkus GS, Owen WF Jr, Lazarus JM, Kay J, Turner JR. Development of gastrointestinal beta-2-microglobulin amyloidosis correlates with time on dialysis. Am J Surg Pathol 22:729-735, 1998
4. Kaiserling E, Krober S. Massive intestinal hemorrhage associated with intestinal amyloidosis. An investigation of underlying pathologic processes. Gen Diagn Pathol 141:147-154, 1995