Duodenal duplication cyst: a potentially malignant disease.

BACKGROUND: Duodenal duplication cysts constitute a rare congenital anomaly of the gastrointestinal tract. A recent meta-analysis of the literature between 1999 and 2009 reported a total of 47 cases of duodenal duplication cysts.1 These abnormalities are mostly diagnosed in infancy and childhood. In rare cases, they can remain asymptomatic until adulthood, and 38 % of patients are diagnosed after age 20 years.1 (,) 2 Duodenal duplication cysts are generally benign lesions; nevertheless, three cases of malignant tumours arising inside have been reported.3 (-) 5

METHODS: In this multimedia article, we illustrated the case of an 18 year-old female patient presenting with recurrent episodes of mild pancreatitis. MRI revealed a cystic structure measuring 2.5 cm in diameter located in the duodenal wall next to the papilla of Vater. Endoscopic ultrasound showed a cystic lesion cephalad to the papilla, protruding into the duodenal lumen. Endoscopic retrograde cholangiopancreatography was not feasible due to the dislocation of the papilla, whose macroscopic aspect was normal. To further elucidate the anatomical relations, 3D reconstruction of the MRI images was performed. There was neither dilatation of the biliary tract nor a visible communication between the common bile duct and the cystic structure. The pancreatic duct also was at distance. Those findings were suggestive of a duodenal duplication. Nevertheless, the differential diagnosis6 of a choledochocele (Todani III) could not be formally excluded. Indication for surgical resection was symptomatic disease in a context of potential malignancy.

RESULTS: By right subcostal incision (video), surgical exploration revealed a soft tissue mass palpable at the second portion of the duodenum. Following duodenotomy, the mucosa was incised cephalad to the papilla of Vater, which could previously be localized by methylene blue injection by a catheter inserted into the cystic duct. The cystic structure was dissected and no communication between the cyst and the biliary tract was individualized. The final diagnosis was made by histological examination showing duodenal duplication. There was neither heterotopic gastric mucosa nor excreto-biliary epithelial layer. There were no signs of malignancy. The postoperative course was marked by hematemesis externalised by the nasogastric tube. We reintervened at postoperative day 2 to ensure hemostasis. A clot was removed from the area of duodenal mucosa without any visible active bleeding. Further recovery was uneventful; the patient was discharged at postoperative day 10 and is actually asymptomatic.

DISCUSSION: The ideal treatment of duodenal duplication cysts is complete surgical resection.7 Due to proximity to the bilio-pancreatic duct, total resection sometimes requires pancreaticoduodenectomy. This major surgical procedure entails the disadvantages of high morbidity and mortality with poor quality of life. In our opinion, this procedure should remain an ultimate option. Less invasive approaches have been proposed, including partial resection or internal derivation.7 Marsupialization is a surgical approach that has been accomplished even endoscopically.1 Nevertheless, these techniques do not provide total resection and leave the risk of degenerescence. As cases of malignancy are reported, we decided to realize a complete surgical excision of the lesion. Three-dimensional reconstruction of the biliary anatomy is an innovative procedure, which allowed us to show the absence of any communication between the cyst and either the common bile duct or the pancreatic duct.8 So, the surgical approach could be specified preoperatively ensuring the integrity of the common bile duct. Duplication cysts could be connected to the pancreaticobiliary ducts in about 29 %.1 Subsequent realization of a total surgical excision combined the advantages of complete resection with minimal invasiveness.

CONCLUSIONS: For relieving symptoms and preventing further complications, such as pancreatitis or malignant transformation, surgical resection of duodenal duplication cysts is indicated. In cases of difficulties to individualize the neighboring anatomical structures preoperatively, 3D reconstruction is a helpful approach to determine the surgical strategy. Enucleation allows a total excision while minimizing the adverse effects and therefore it is our treatment of choice for duodenal duplication cysts without communication.