P0445 - An Unusual Cause of Chronic DIarrhea

Jeffrey Rebhun, MD, Rohit Agrawal, MBBS, Constantine Melitas, MD
University of Illinois at Chicago, Chicago, IL

Introduction: Chronic diarrhea is a common clinical complaint, however when this patient presented with several other systemic symptoms the workup required a broader differential and a more invasive workup. We present a case of systemic amyloidosis presenting as chronic diarrhea.

Case Description/Methods: A 67-year-old female with a past medical history of hypertension, hyperlipidemia, and end-stage renal disease (ESRD) on hemodialysis presented to the emergency department after a syncopal episode. She reported a 3-month history of watery, non-bloody diarrhea, poor oral intake, epigastric abdominal pain along with weight loss of 20 pounds. Vitals were notable for orthostatic hypotension which partially responded to a small bolus of fluid. She had microcytic anemia of Hb 11.3 mg/dL, mean corpuscular volume 73 fL without iron deficiency. Her hospital course was complicated by pulseless electrical activity (PEA) arrest and bradycardia with ROSC achieved. Repeat EKG findings showed low voltage complexes. She underwent esophagogastroduodenosopy (EGD) and colonoscopy for chronic diarrhea and weight loss. EGD showed food residue in the stomach suggestive of gastroparesis (Fig.A). Biopsies from the esophagus, stomach and duodenum were taken. Colonoscopy showed no large polyps, masses or significant mucosal abnormalities (Fig.B). Hematoxylin and eosin stains of the esophagus, stomach, duodenum (Fig.C), and colon showed thick walled blood vessels surrounded by proteinaceous deposition. Congo red stain was performed on paraffin sections of specimens revealing amyloid deposits (Fig.D). The presentation of restrictive cardiomyopathy, low voltage complexes on EKG, autonomic neuropathy, gastroparesis, ESRD, and diarrhea all were signs and symptoms consistent with primary amyloidosis.

Discussion: Systemic amyloidosis (SA) is an uncommon disorder in which the deposition of misfolded proteins leads to a number of vague symptoms including fatigue, edema, weight loss, and orthostatic hypotension. The kidney and the heart are the most frequently involved organs, however deposition in the gastrointestinal tract is also possible and its accessibility makes endoscopy a common diagnostic tool. Diarrhea is the most common gastrointestinal symptom of SA, which is thought to be secondary to bacterial overgrowth within the small intestine, protein losing enteropathy, and malabsorption. Findings on endoscopic evaluation are non-specific and include erythema, ulcerations, erosions, or friability, but most commonly normal appearing mucosa.



Figure: A: Normal stomach with food residue
B: Normal appearing mucosa of the ascending colon
C: Homogeneous eosinophilic deposits of amyloid in submucosal blood vessels of the small bowel (conventional haematoxylin and eosin-stained section 20 x)
D: Reddish-orange appearance of amyloid protein deposit in submucosal blood vessels of small bowel (congo red-stained section 20x)


Disclosures:
Jeffrey Rebhun indicated no relevant financial relationships.
Rohit Agrawal indicated no relevant financial relationships.
Constantine Melitas indicated no relevant financial relationships.


Jeffrey Rebhun, MD, Rohit Agrawal, MBBS, Constantine Melitas, MD. P0445 - An Unusual Cause of Chronic DIarrhea, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.