S2203 A Rare Case of Amyloid-Induced Colonic Pseudo-Obstruction

Abstract

Introduction: Colonic pseudo-obstruction is a rare complication of AL Amyloidosis that is described as a diffuse colonic dilation without underlying mechanical cause. In AL Amyloidosis, extracellular protein deposits disrupt tissue structure and function. Manifestations of colonic involvement of AL Amyloidosis include chronic diarrhea, weight loss, abdominal pain, and pseudo-obstruction. Here we present a patient with worsening abdominal pain and distention, found to have colonic pseudo-obstruction likely from AL Amyloidosis. Her symptoms improved with colonic decompression and with the utility of prokinetic agents. Case Description/Methods: A 79-year-old female presented with 3 days of progressively worsening abdominal pain and distention, with associated constipation. Her past medical history was significant for anemia, AL-Amyloidosis diagnosed 4 months prior to arrival, and PEG placement 3 weeks prior to arrival due to worsening dysphagia secondary to macroglossia. Vital signs were normal. She did not appear in acute distress and was hemodynamically stable. Pertinent examination findings included abdominal distention, decreased bowel sounds, and diffuse abdominal tenderness. Pertinent labs included WBC 5.6 k/uL, albumin 2.1 g/dL, AST 39 U/L, ALT 43 U/L, ALP 196 U/L, and total bilirubin 0.3 mg/dL. Clostridium difficile, giardia lamblia, salmonella, and stool occult blood were negative. CT abdomen and pelvis revealed gaseous distention of the transverse colon and diffuse colonic wall thickening, as displayed in figure 1. Colonoscopy revealed diffuse dilation of the transverse colon, with components of inflammation including friability and loss of vascularity. Decompression was successfully performed through the colonoscope. The patient tolerated the procedure well and had marked improvement of abdominal distention and pain. Her percutaneous tube feeds were reinitiated and tolerated well. (Figure) Discussion: Colonic pseudo-obstruction is a rare complication of AL Amyloidosis that is caused by deposits of protein in extracellular tissue. AL Amyloidosis is a multisystem disease that rarely presents with colonic manifestations. However, colonic manifestations may be the sole presentation of AL Amyloidosis. Colonic pseudo-obstruction remains a clinical challenge and can lead to bacterial overgrowth and malnutrition. Here we demonstrate successful air decompression of a colonic pseudo-obstruction due to AL Amyloidosis. We hope to increase awareness of AL Amyloidosis as an etiology colonic pseudo-obstruction.Figure 1.: CT Abdomen Pelvis reveals diffuse gaseous distention of the transverse colon with bowel wall thickening.