Diagnosis And Treatment Of Ectopic Pancreas In The Alimentary Tract And The Value Of Endoscopic Ultrasonography

Background and aims:Ectopic Pancreas(EP),refers to an relatively rare congenital abnormality in which pancreatic tissue has been found outside the normal pancreas gland and without any kind of vascular or other anatomical connections to the orthodox gland.It is most often found in the alimentary tract and presented as a submucosal lesion.Endoscopic ultrasonography(EUS)can be used to clearly and accurately observe the digestive tract lumen and its surrounding structure,echo patterns and other characteristics,therefore,has been widely used in the diagnosis and differential diagnosis of a variety of digestive tract submucosal lesions in recent years.The aim of this study is to summarize the experience of diagnosis and treatment of ectopic pancreas in our hospital,and to analyze the clinical characteristics of ectopic pancreas,so that we can further deepen the cognition of the disease,and properly appraise the value of endoscopic ultrasonography in the diagnosis and treatment of ectopic pancreas.Methods:We collected patients diagnosed by the pathological department with ectopic pancreas in a total of 138 cases and patients diagnosed by EUS with the ectopic pancreas and later obtained pathological results through surgical or endoscopic treatment in a total of 75 cases from January 1,2010 to January 1,2017 in the First Affiliated Hospital of Zhejiang University.Then we retrospectively reviewed their demographic characteristics,occurrence sites,clinical symptoms,endoscopic and endoscopic ultrasonic images,CT images,diagnosis and treatment,follow-up outcomes and so on.Statistical software SPSS 20.0 was used for data process and-analysis.Results:1.Of the 138 patients with EP,76 males and 62 females had an average age of 46.12±14.06.Almost all the lesions occurred in the digestive tract with the vast majority of ectopic pancreas in the stomach(61%)and duodenum(16%),only a few located in the jejunum(16%)and ileum(6%).Only 1 case found in the gallbladder.2.Very few gastric or duodenal EP can cause gastrointestinal bleeding(2 cases),obstructive jaundice(1 case)and other clearly related symptoms.The rest are mostly asymptomatic or with abdominal pain,abdominal distension and other non-specific symptoms.Jejunum EP are mostly inadvertently obtained during abdominal surgeries,only a small number of jejunum EP(2 cases)can cause gastrointestinal bleeding or/and abdominal pain.Ileal EP often concur with small bowel intussusception,diverticulum and manifest abdominal pain and bloody stool.The only case of gallbladder ectopic pancreas was asymptomatic;it was found during a checkup examination and then surgically removed.3.Gastric duodenal EP lesions are most common in the gastric antrum(59%),especially in the larger curve side.It often appears as broad base submucosal uplift lesion under endoscopy examination,with a smooth and normal surface(71%);only a few cases can be seen with a surface depression or a clearly opening outlet.Ultrasound endoscopic lesions with an average length of 14.5 ± 7.6mm,mostly originated from the submucosa(67.2%)or the muscularis propria(21.9%),sometimes involving multiple levels.EUS echo was predominantly low echo pattern(50.0%)and moderate echo pattern(40.6%),often uneven(56.3%),while the boundary was mostly clear(90.6%).Some cases(9.4%)can be seen with a behind muscularis propria thickening.A typical ductal-like echo structure was found only in 28.1%of the cases.4.The sensitivity of EUS examination to gastric duodenal EP was 43.08%and the positive predictive value was 37.33%.26%of the gastroduodenal EP were mistakenly diagnosed as stromal tumors under EUS,and 6%were misdiagnosed as polyps(including proliferative polyps and inflammatory fibrous polyps).Cases misdiagnosed as ectopic pancreas under EUS include mucosal chronic inflammation(25%),proliferative polyps(17%),inflammatory fibrous polyps(13%),stromal tumors(8%)and some other less common lesions.CT examination can only find 57.3%of the gastroduodenal ectopic pancreas lesions,but rarely directly diagnosed as EP.5.The treatment strategy for gastroduodenal EP is generally endoscopic;only when misdiagnosed as other diseases or endoscopic treatment is not successful,surgery becomes an option.Jejunum EP generally does not cause symptoms,and needs no treatment.Ileal EP can often concur with small bowel intussusception,small intestine diverticulum and cause abdominal pain and bloody stool,so that often need surgery and even emergency surgery.Generally,ectopic pancreas after treatment will not come back.Conclusion:Ectopic pancreas mostly occurs in the stomach,duodenum,jejunum and ileum,especially in the large curve side of the gastric antrum.Only a few directly cause clinical symptoms,mainly the ileal ectopic pancreas.Ectopic pancreas under regular endoscope showed no specificity,the typical top depression or opening of the lesion is rare.EUS,as the most important preoperative examination of the gastroduodenal ectopic pancreas,can observe more deeply to the lesion,which is of great value in the diagnosis and treatment of ectopic pancreas,but its sensitivity and positive predictive Values are both relatively low,and need to be further improved.Jejunal and ileal ectopic pancreas' preoperative examination mainly rely on abdominal CT,which cannot correctly detect and diagnose the disease in most cases.Gastric and duodenal ectopic pancreas' treatment under endoscopy is safe and effective,and Jejunal and ileal lesions with symptoms still rely on surgical resection.