Case Presentation:

An 85–year–old Hispanic female with history of hypertension presented with abdominal pain, diarrhea and increased abdominal distension for 4 days. She also had increased fatigue, dysphagia and edematous legs for 4 months. She denied shortness of breath, chest pain, fever or dysuria. On examination, she was alert and oriented but fatigued. There was no jaundice or macroglossia. She had decreased bibasilar breath sounds, normal heart sounds, distended abdomen without hepatosplenomegaly and +2 lower extremity edema. Initial labs showed CBC, electrolytes, creatinine, lipase, bilirubin and lactate within normal limits. Her albumin was found to be 1.5 g/dL. Stool was negative for helminthic ova, giardia and clostridium difficile antigen. Chest X–ray showed small pleural effusions. CT abdomen revealed diffuse fluid–filled dilation of the small bowel. Upper GI series showed moderate presbyesophagus and spasm at the esophagogastric junction. Esophagogastroduodenoscopy showed multiple soft nodules in the gastric antrum with normal esophagus and duodenum. Esophageal and duodenal biopsy showed amorphous eosinophilic material which demonstrated apple–green birefringence with Congo red stain under polarized light suggestive of Amyloidosis. Alcian Blue, Periodic acid–Schiff, Warthin–Starry stain were negative for GI metaplasia, Whipple’s disease and Helicobactor pylori respectively. Etiological work–up for amyloidosis included ESR 4 mm/h, C–reactive protein 1.3 mg/dL, Calcium 8.6 mg/dL, urine protein 384 mg/24 h and negative Rheumatoid factor and Antinuclear antibodies. Serum protein electrophoresis detected a paraprotein spike at 1.44 g/dL. Urine protein electrophoresis showed a faint gamma band. Immunofixation revealed increased IgG/Lamba monoclonal immunoglobulin suggestive of MGUS. Immunohistochemistry and flow cytometry from peripheral smear were negative for clonal plasma cells or malignant B–cells. Echocardiography showed no infiltrative cardiomyopathy. The patient was started on tube feeds because of dysphagia. Her clinical status continued to deteriorate with worsening dyspnea and severe malnutrition secondary to protein losing enteropathy. Percutaneous gastrostomy tube was suggested. However, after extensive discussions, the family refused and decided to withdraw all life support measures and the patient died.

Discussion:

MGUS is defined by the presence of a serum monoclonal protein concentration less than 3 g/dL. It has rarely been shown to be complicated by amyloidosis. Our case describes a rare association of localized GI amyloidosis with MGUS. No clinical, laboratory and imaging findings were consistent with cardiac, renal and liver involvement ruling out systemic amyloidosis.

Conclusions:

As MGUS can be complicated by amyloidosis and Multiple Myeloma transformations, follow–up of these patients and further research is needed to establish guidelines for better management.