Systemic amyloidosis as a cause of chronic diarrhea after gastric surgery. Literature review.

Amyloidosis with gastrointestinal involvement is a rare cause of chronic diarrhoea, and should be considered especially in adult patients with intestinal malabsorption and extra GI manifestations. We present the case of a male patient who, after an oncological gastrectomy, presented with chronic diarrhea that did not respond to treatment and, after study, the cause of the diarrhea was finally found. Primary systemic light chain amyloidosis (AL) initially presents as chronic diarrhea and weight loss after gastrectomy. Immunohistochemistry was completely negative for amyloid A, which virtually rules out AA amyloidosis. With regard to the immunoglobulin chains, an amyloid signal was observed for both light chains, with a predominance of lambda light chain but not entirely conclusive. This situation is not uncommon since amyloid, whatever its chemical nature, can annex serum proteins, including immunoglobulin chains. In the case of chronic diarrhea, the possibility of amyloidosis should be kept in mind, especially in the case of weight loss.