the presence of pancreatic tissue outside its normal localization and without anatomic and vascular continuity with the normal pancreas is termed heterotopic pancreas ( hp ) ; pancreatic rests , ectopic , aberrant , or accessory pancreas are the other terms to describe the entity .
hp may occur throughout the gastrointestinal tract , but has a propensity to affect the stomach , duodenum , jejunum , meckel 's diverticulum , and ileum .
less frequently , it is observed in the liver , gallbladder , bile duct system , and papilla of vater .
hp is known to be associated with various associated anomalies like malrotation , small intestinal atresias , biliary atresias , congenital diaphragmatic hernias , meckel 's diverticuli , annular pancreas and esophageal atresias .
there have been isolated case reports of the presence of hp within the choledochal cyst ( cc ) .
a 9-year - old boy presented with features of gastric outlet obstruction for 1 month .
he was operated for cc type 1 at the age of 4 months at the same center ; complete excision of cyst with roux - en - y hepaticojejunostomy was done .
magnetic resonance cholangio - pancreaticography ( mrcp ) done prior to first surgery had shown pancreaticobiliary malunion ( pbmu ) , cc and dilated pancreatic duct , suggestive of chronic pancreatitis [ figure 1 ] .
no annular pancreas or obvious pancreatic rests were noted at the mrcp or subsequent surgery .
upper gastrointestinal ( gi ) contrast study revealed partial obstruction of the first part of duodenum [ figure 2 ] .
upper gi endoscopy revealed the lumen of first part of the duodenum completely obliterated by a large polypoidal mass ; the endoscope could not be negotiated beyond the first part of duodenum .
magnetic resonance cholangio - pancreaticography showing pancreaticobiliary malunion , type i cc and dilated pancreatic duct upper gastrointestinal contrast study showing near - total obstruction of first part of duodenum on exploration , the first part of duodenum was found to be severely inflamed and thickened with near complete obliteration of its lumen .
the roux - en - y loop of the previous hepaticojejunostomy was 5 cm away from the duodenal lesion .
excision of 2.5 cm of distal stomach , pylorus and first part of duodenum with gastroduodenostomy akin to billroth i procedure was done .
histopathologic examination of the entire excised specimen revealed transmural acute on chronic inflammation and diffuse fibrosis .
there were submucosal heterotopic pancreatic rests in the excised duodenum , though there were no abnormal cells in the excised pylorus and the stomach [ figure 3 ] .
heterotopic pancreatic rests in the submucosa of the duodenal partition ( h and e ,  40 )
the proposed theory is that during rotation of foregut in a fetus and fusion of dorsal and ventral parts of pancreas , small islands of pancreatic rests are carried away and continue to develop at this aberrant location .
hp is seen in 12% of patients as autopsy findings and 1 in 500 of upper abdominal surgeries .
our case was considered to be a type 2 ectopic pancreas , based on heinrich classification .
however , they may present with obstruction , lump , gi bleeding , etc . , depending on the size and location of hp .
correct preoperative diagnosis is usually not possible and the eventual diagnosis is made on surgical exploration and pathological examination .
clinically significant lesions are greater than 1.5 cm in maximum diameter and are adjacent to or directly involve the mucosa .
but most of the cases of hp causing gastric outlet syndrome have been described in adults .
such an occurrence has been occasionally reported in children and rarely reported in infants and neonates too .
radiological investigations like computed tomogram ( ct ) scans , endoscopic ultrasonograms and nuclear scan studies assist in preoperative diagnosis , but with difficulty .
upper gi endoscopy , though helpful in certain patients presenting with submucosal nodules , was not helpful in the preoperative diagnosis in our case .
therefore , surgery is frequently needed to make a definitive diagnosis and plan further management and also because differential diagnosis includes leiomyomas , lymphomas , carcinoid tumors , gastrointestinal stromal tumors ( gist ) and other malignancies . on review of available literature on hp
, we found that all the pathologies known to affect the pancreas can also be seen in hp .
hence , we feel that whenever hp is encountered incidentally or because of complication , it warrants excision . keeping this in mind
, we performed the excision of the lesion rather than a simple bypass such as posterior gastrojejunostomy .
 a 9-year - old boy presented with duodenal pancreatic rest causing obstruction and required surgical intervention . 
 he had been treated at the age of 4 months for a choledochal cyst . 
 both choledochal cyst and heterotopic pancreas are entities that are commonly encountered in children , but the incidental presence of both the entities in the same child , albeit presenting metachronously , is extremely rare . 
INTRODUCTION
CASE REPORT
DISCUSSION