A Rare Discovery of Colonic Amyloidosis

Abstract

75 year old female with a past history of hypertension, recurrent melena and breast cancer who presents from her PCP for evaluation of anemia, fatigue, anorexia, and weight loss She was previously evaluated for gross hematochezia requiring blood transfusion. On admission, the patient underwent an abdominal CT scan significant for a diffuse reactive/infiltrative process with adenopathy along the aorta and iliac veins. Serum protein electrophoresis revealed a monoclonal spike in the gamma region corresponding to an IgM kappa paraprotein. Colonoscopy was performed showing diverticulosis and multiple polyps with a large mass in the sigmoid colon. Biopsies were significant for colonic amyloidosis. Amyloidosis is a generic term that refers to the extracellular tissue deposition of a variety of serum proteins, many of which circulate as constituents of plasma. The most common causes of systemic amyloid deposition are AL amyloid caused by a plasma cell dyscrasia and AA amyloidosis due to ongoing or recurring inflammation from chronic disease. Patients with symptomatic gastrointestinal amyloidosis usually present with one of four syndromes: gastrointestinal bleeding, malabsorption, protein-losing gastroenteropathy, and, less often, gastrointestinal dysmotility. While patients with AA amyloidosis usually present with diarrhea and weight loss, patients with AL amyloidosis usually present with constipation, mechanical obstruction, or chronic intestinal pseudo-obstruction. The diagnosis of gastrointestinal amyloid requires a tissue biopsy with positive staining of amyloid by Congo red or the presence of amyloid fibrils on electron microscopy. Although the gastrointestinal complications can result in significant morbidity, they are not usually the cause of death, which is most often due to renal failure, restrictive cardiomyopathy, or ischemic heart disease. Therapy is directed at the gastrointestinal manifestations and at the underlying cause of amyloidosis.Figure 1Figure 2Figure 3