Duodenal duplication cyst: Rare cause of abdominal pain in adults

A 31-year-old woman was referred to our hospital due to a right hypochondrium cystic lesion detected in an abdominal ultrasound. The patient had recurrent complaints of epigastric pain and postprandial fullness and was medicated with proton-pump inhibitors. She had unremarkable medical history and the laboratory tests were normal.

Contrast-enhanced CT scan (figure 1) revealed a well-defined cystic lesion located in the pyloroduodenal region, adjacent to the pancreatic head. The lesion was bilobed and thin-walled with homogeneous internal fluid density, and measured 6 cm in diameter. There were no septations, calcifications, enhancing solid components or surrounding inflammatory signs.

The MRCP images (figure 2) confirmed the thin-walled cystic lesion with homogeneous internal fluid sign, contiguous with the wall of the second portion of the duodenum (D2), without luminal communication. There was no connection with the gallbladder nor the common bile duct, which had a prominent caliber due to distal extrinsic compression. There was no upstream dilation of the intrahepatic bile ducts. The pancreas had normal morphology and signal intensity. There was no pancreatic duct dilatation.

Background

Duodenal duplication cysts (DDC) are a rare congenital anomaly, accounting for 2% to 12% of digestive tract duplications[1].

Clinical Perspective

DDC are usually detected prenatally or in infancy[1,2]. However, they may remain asymptomatic until adulthood[1,3]. The size, location, mucosal pattern and eventual associated complications generate a varied spectrum of clinical manifestations[2,4].  The symptoms are usually nonspecific and the most common are abdominal pain, nausea and/or vomiting[1,3,4]. The most frequent complications are pancreatitis (affecting 53% of patients), biliary obstruction, intussusception and intestinal bleeding[1,3,5].

Imaging Perspective

Ultrasonography is commonly the first imaging technique performed[3]. DDC presents as an anechoic cystic lesion in the pyloroduodenal region, containing debris[1]. The majority are located medial or posterior to the second or third parts of duodenum[5]. It is double-walled, with an inner hyperechoic rim correlating with the mucosa-submucosa and an outer hypoechoic layer representing the muscularis propria (gut signature sign)[4], and may show muscular peristalsis[1,3], which are distinctive features.

CT and MRI are useful to confirm the diagnosis, characterize the anatomical relationship with the surrounding structures and detect potential complications[3]. DDC are fluid-filled structures, attached to the medial wall of the descending duodenum[1]. Occasionally, cyst wall calcification is recognized[1].

MRCP and ERCP are useful to characterize eventual associated biliary and pancreatic ductal abnormalities[1], namely biliary duct dilation and acute pancreatitis.

The definitive diagnosis is confirmed with histopathologic analysis, which demonstrates an alimentary mucosal lining, smooth muscle coat, and intimate attachment to the native gastrointestinal tract[2,3].

Outcome  

Complete surgical resection is the ideal treatment for both symptomatic and asymptomatic patients, given the potential complications and the risk of malignant transformation[1,4]. Endoscopic marsupialisation is also a therapeutic option[5]. 

The prognosis is excellent when complete excision is achieved and there are no histological evidence of malignancy[4].

Our patient underwent successful complete surgical resection and the anatomopathological study confirmed the duodenal duplication cyst with ectopic gastric mucosa. The post-operative period was complicated with acute pancreatitis which was treated conservatively.

Take Home Message / Teaching Points

Duodenal duplication cysts are rare congenital gastrointestinal tract malformations, seldomly reported in adults, with nonspecific clinical manifestations.

Imaging studies are useful to stablish the diagnosis and to characterize the relationship with the adjacent anatomical structures, which is essential for planning the surgical approach.

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