Unusual case of abdominal tenderness

A 58yearold woman presented with abdominal pain for over 7 months. Physical examination revealed macroglossia (figure 1) and severe tenderness of the periumbilical region. Laboratory investigation yielded elevated liver enzymes, hypoalbuminaemia, hyperlipidaemia, positive urine protein, brain natriuretic peptide 2520 pg/mL and cardiac troponin I 178 ng/L. Coagulation function was not markedly affected. Transthoracic echocardiogram showed left ventricular hypertrophy, diastolic dysfunction with normal left ventricular ejection fraction. Gastroscopy presented congestion, swelling, roughness and erosion of the gastric mucosa. Colonoscopy revealed rectal polyps. Abdominal CT and CT enterography demonstrated hepatosplenomegaly, renomegaly, dilation and effusion of the intestine and thickening of the ascending and transverse colonic wall (figure 2). Electromyography revealed that the skin sympathetic response amplitude of right upper limb was decreased, which indicated impaired peripheral and autonomic nervous system. Mesenteric CT angiography and bone marrow biopsy were normal.