A 59-year-old woman with body mass index 46 (weight 137 kg) presented with a 2-month history of diarrhoea and weight loss. There was no significant past medical history apart from atrial fibrillation controlled with digoxin. Clinical examination was normal and there was no abdominal tenderness or masses. Blood tests including full blood count, liver function tests, amylase, thyroid function, immunoglobulins, serum electrophoresis and short synacthen test were normal. Stool cultures were negative. Serum albumin was 24 g/dl without proteinuria. Gastroscopy and colonoscopy were normal and biopsies showed no evidence of inflammatory bowel disease or coeliac disease. Abdominal ultrasound showed gallstones and a non-dilated biliary tree.
She had persistent diarrhoea and weight loss of 70 kg over the next 26 months but remained well. Barium follow through revealed slow intestinal transit but no focal abnormality. Faecal elastase and p-amino benzoic acid were normal. CT abdomen was normal and there was no intra-abdominal lymphadenopathy. Fasting gut hormone profile (vasoactive intestinal peptide, pancreatic polypeptide, gastrin, glucagon, chromogranin A&B, somatostatin) was normal. Octreotide and SeHCAT scans were normal, as was endoscopic ultrasound. Lactose breath test was positive.
She was admitted to hospital as an emergency following a collapse and was diagnosed with a pulmonary embolism. An echocardiogram revealed asymmetric left ventricular hypertrophy with slight speckling of the myocardium. During her inpatient stay she developed melaena and fresh rectal bleeding. Repeat oesophago-gastro-duodenoscopy showed prominent thickened gastric mucosa (see ). Colonoscopy showed intramucosal haematomas in the sigmoid (see ).
Narrow band and white light images of the gastric body: prominent thickened gastric mucosa.
Intramucosal haematomas of sigmoid colon.
Congo-red staining of the gastric biopsies was negative, but electron microscopy was strongly positive for amyloid (see and ). She was referred to for a serum amyloid protein scan which confirmed amyloid of the stomach, small intestine, colon and heart.
Electron microscopy of gastric biopsy, magnified ×4600: peri-vascular amyloid deposition.
Electron microscopy of gastric biopsy, magnified ×130 000: amyloid protein filaments.