[Gastrointestinal amyloidosis in IgG-chi-light chain plasmacytoma. Diagnostic problems despite advanced changes]

A 50-year-old man with an IgG-chi light chain multiple myeloma stage IIIA, developed--in a phase of low disease activity, after 18 months of an uncomplicated course--marked malabsorption syndrome with 20 kg weight loss, diarrhoea and meteorism. Although the H2-breath test indicated intestinal bacterial colonisation, neither antibacterial treatment with trimethoprim/sulphamethoxazole and metronidazole nor prokinetic treatment with cisapride (30 mg daily) and erythromycin (1 g twice daily) improved the symptoms. Suspected amyloidosis was not demonstrable at first, despite repeated step biopsies of stomach, duodenum and rectum. Amyloidosis of the entire gastrointestinal tract was proven only by repeated biopsies deep into the submucosa. Despite treatment of the underlying disease with melphalan and prednisone (Alexanian's scheme) the amyloidosis advanced further to involve liver, spleen, lung, kidneys and heart. The patient died, 2 years after diagnosis of the multiple myeloma, from recurrent pulmonary emboli due to atrial fibrillation.