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Paper text:
ectopic pancreas , also called a heterotopic or aberrant pancreas , is defined as pancreatic tissue lying outside its normal location and lacking anatomic or vascular connections with the pancreas .
this usually asymptomatic condition is found incidentally at laparotomy or autopsy in the stomach , duodenum , small intestine , meckel 's diverticulum , or biliary tract [ 1 , 2 ] . it is found in approximately 1 to 2% of autopsy cases .
it has also been reported that more than 85% of cases occurred in the gastrointestinal wall . of them
, 30% occurred in the duodenum , 25% in the stomach , 15% in the jejunum , 5% in the ileum , and 5% in meckel 's diverticulum .
adenocarcinoma originating from an ectopic pancreas has been reported in several cases in the literature [ 4 , 5 , 6 , 7 , 8 ] . in this report
, we describe a case of invasive ductal carcinoma arising from an ectopic pancreas in the stomach .
a 75-year - old woman came to our hospital presenting with epigastralgia in february 2000 .
carcinoembryonic antigen ( cea ) was 8.7 ng / ml , and carbohydrate antigen 199 ( ca199 ) was 287.4 u / ml . gastrointestinal endoscopy was performed and revealed a gastric submucosal tumor ( smt ) at the middle corpus , posterior wall and lesser curvature of her stomach .
the smt had obviously enlarged with a lobular surface from when examined 2 years previously ( fig .
1 ) . computed tomography ( ct ) revealed an intramural cystic mass , 4.0 cm , located in the lesser curvature of the stomach ( fig .
, we found a 2.0  2.0  2.0 cm elastic mass fused to the other tumor .
since the tumor had no connection with the neighboring gastric wall , it was easily resected with the capsulized tumor .
histological examination of the submitted material shows the resected part of the stomach with submucosal cystic tissue consisting of an ectopic pancreas with cystic or papillary hyperplasia of ducts , mature clusters of pancreatic acini , langerhans islets and foci of moderately differentiated tubular adenocarcinoma in fibrous stroma , located in the submucosa and subserosa through the muscle layers of the stomach with no marked mucosa ( fig .
microscopically , invasive ductal carcinoma arising from the ectopic pancreas was observed in the stomach .
the postoperative course was uneventful , and the patient has been healthy without any evidence of disease recurrence for 11 years .
ectopic pancreas tissue in the stomach is most commonly found in the antrum and is also seen relatively frequently along the greater curvature and posterior and anterior walls , whereas it rarely occurs along the lesser curvature .
von heinrich   proposed three types of heterotopic pancreas in 1909 ; thereafter , his classification was modified by gaspar fuentes in 1973 , acquiring its final form .
type i : heterotopia consists of typical pancreatic tissue with acini , ducts , and islet cells similar to those seen in a normal pancreas .
type ii : heterotopia is composed of pancreatic ducts only , referred to as canalicular variety .
type iv : heterotopia is made up of islet cells only [ 10 , 11 ] .
our case , a type of heterotopic pancreas , seemed to be categorized in type i , because typical pancreas tissue with acini , ducts , and islet cells was seen in the pathological examination .
the origin of ectopic pancreas is unknown ; it is possible that during rotation of the foregut and fusion of the ventral and dorsal parts of the pancreas in early fetal life , small pieces of tissue become detached from the forming organ , leading to entrapment in different locations .
malignant transformation in an ectopic pancreas has been reported in less than 15 cases in the literature [ 4 , 5 , 6 , 7 , 8 , 12 , 13 ] .
criteria have been proposed for the diagnosis of carcinoma from an ectopic pancreas as follows : ( 1 ) the tumor must be located within or very close to the ectopic pancreas tissue , ( 2 ) transition between pancreas structures and carcinoma must be identified , and ( 3 ) the nonneoplastic pancreatic tissue must comprise fully developed acini and ducts .
preoperative diagnosis of ectopic pancreas malignancy may be difficult with imaging studies such as ct and radiographic study .
endoscopic ultrasound ( eus ) is typically used to evaluate submucosal lesions in the upper gastrointestinal tract .
eus also allows the use of targeted fine needle aspiration biopsy ( fnab ) , particularly helpful for the final diagnosis ; however , cytological examinations are inconclusive in about 50% of cases .
one author reported that adenocarcinoma arising from an ectopic pancreas seemed to have a somewhat better prognosis than those arising from the pancreas itself , probably due to earlier presentation . in the literature ,
only ten cases have been reported , with a survival time of between six months and ten years , and all with a life expectancy longer than in the case of orthotopic pancreas surgery . in the present case ,
the patient has survived for more than 11 years . in summary , we report a rare case of malignant transformation of an ectopic pancreas of the gastric wall in a patient who has survived during long - term follow - up after surgery .
a case of invasive ductal carcinoma of an ectopic pancreas in the stomach in a 74-year - old woman is presented . 
 a 4.0 cm gastric submucosal tumor ( smt ) was resected surgically . 
 histologically , the tumor showed cystic tissue consisting of an ectopic pancreas with foci of a moderately differentiated tubular adenocarcinoma . in this tumor , small pancreatic tissues , 
 acini , langerhans islets , and ductular cells were detected in the gastric smt . 
 the patient has experienced long - term survival . 
 the incidence of pancreatic cancer of an ectopic pancreas is rare , and the etiology of this disease is discussed in the literature .