Clinical Manifestations And Endoscopic-abdominal CT Correlation In Diagnosis Of Gastrointestinal Amyloidosis

Background and aimAmyloidosis is a group of disorders caused by the extracellular deposition of insoluble amyloid fibrils resulting in organ dysfunction.Gastrointestinal(GI)amyloidosis is rare and has a poor prognosis.Early diagnosis and treatment are required.Due to the non-specificity of clinical and endoscopic manifestations,the disease is always difficult to diagnose.The mucosal pathology is necessary for a definitive diagnosis,but the positive rate of biopsy is still unsatisfactory.We hypothesize a combination of endoscopy and abdominal CT to guide the selection of biopsy sites under endoscopy that may increase the positive rate of biopsy.MethodsWe identified 159 patients diagnosed with amyloidosis at Sir Run Run Shaw hospital between March 2016 and January 2020.We retrospectively investigated 18 patients with pathologically proven amyloidosis of digestive tract by gastrointestinal endoscopy.Clinical date,including general characteristics,potential involved organs,survival time,and endoscopic and abdominal CT results were analyzed in these patients.We summarized the relationship between endoscopic findings and relative abdominal CT changes.Results:Abdominal discomfort(70.0%)was the main symptom for patients whose upper digestive tract involvement.41.2% of the patients had multiple organs involved,and the heart was the most common involved organ in the upper digestive tract affected(50.0%).The 1-year survival rate was 62.2% by the time of follow-up.The highest frequency of amyloid deposition was gastric antrum(55.6%),followed by duodenum(33.3%).The positive biopsy rate in these two parts was 64.3% and 68.4% respectively.GI tract wall thickening was found in 78.6% of patients by abdominal CT.We found 92.9% of the patients had at least one abnormal change in gastrointestinal endoscopy or abdominal CT through the analysis of all biopsy-positive sites,of whom 35.7% had both endoscopic and abdominal CT changes.Although some biopsy-positive sites in 4patients showed abnormalities on abdominal CT,there were normal under endoscopy.Conclusion:Gastrointestinal amyloidosis is a rare disease with a poor prognosis.It's clinical symptoms,computed tomography and endoscopic presentations were varied and non-specific.We suggest biopsy specimens should be taken from both gastric antrum and duodenum.These two segments are more easily affected and have relatively high positive biopsy rate.Biopsy following the indication of endoscopy and CT scan,especially in those patients with normal endoscopic results,could increase the diagnosis rate of Gastrointestinal amyloidosis.