A 39-year-old female with no significant past medical history presented with intense epigastric, colic pain for the three previous days. Laboratory studies showed mild and isolated CRP elevation (1.9 mg/dL); liver function tests and pancreatic enzymes were within normal range.

An abdominal CT scan was performed and revealed a solid, duodenal (D2/D3) endophytic polypoid lesion, with 26mm; biliary tree and pancreas were normal (Figure 1).

Figure 1 (abdominal CT, coronal view). Duodenal (D2/D3) endophytic polypoid lesion.


Upper endoscopy (and duodenoscopy) identified a 30mm large subepithelial lesion, distal to the duodenal papilla, with ulcerated top, suggestive of GIST (Figures 2A and 2B).

Figures 2A (upper endoscopy, D2) and 2B (duodenoscopy). Subepithelial lesion distal to the duodenal papilla (black circle) with an ulcerated top.


EUS examination confirmed a peripapillary subepithelial lesion with 25mm and massively calcified, with posterior acoustic shadowing (transition zone undefined) (Figure 3); the common bile duct was normal (Figure 4).

Figure 3 (EUS, D2). Subepithelial lesion massively calcified, showing acoustic shadowing (transition zone/ layer undefined).

Figure 4 (EUS, deep D2). Normal distal (intrapancreatic) common bile duct (white circle).


Multidisciplinary discussion and iconography review raised the diagnostic suspicion of a gallstone impacted in the duodenal wall through a peripapillary bilioenteric fistula. Duodenoscopy was repeated at day 6 but, instead of the lesion previously seen, there was now a large peripappilary orifice, suggestive of a bilioenteric fistula (40mm large after contrast injection and guide-wire exploration) (Figure 5).

Figure 5 (fluoroscopic image). Large peripappilary orifice, suggestive of bilioenteric fistula (guide-wire exploration).


There was spontaneous and complete abdominal pain remission in less than a week after admission. Magnetic ressonance cholangiopancreatograhy (MRCP) was normal 3 months after discharge.



Biliary-enteric fistulas represent the most common forms of biliary fistulas and are usually associated with gallstone disease. In rare instances, an opening in the duodenum close to the duodenal papilla may be seen, representing a fistulous communication between the duodenal wall and the bile duct (choledochoduodenal fistula) or the gallbladder (cholecystoduodenal fistula).

There are only two published case reports of parapapillary fistula with impaction of a gallstone into the duodenal wall.1,2

The case presented was particularly challenging as its endoscopic and ultrasonographic appearance mimicked that of a calcified subepithelial lesion with ulcerated top, such as GIST. Most common subepithelial lesions found in the duodenum are GISTs, leyomiomas, lipomas and carcinoids and EUS has a major role in the differential diagnosis.3 These lesions may occasionally show calcification, usually focal or punctate. However, massive calcification is extremely rare (it has been described in a few cases of GIST)4 and may point to an alternative diagnosis such as an impacted gallstone into the duodenal wall, particularly if found in D2.

Multidisciplinary discussion and iconography review were crucial for the correct diagnosis, avoiding unnecessary surgery.



1. Okabe Y. et al. Successful endoscopic extraction of a large impacted choledocholithiasis in the ampulla of vater: two interesting cases. Digestive Endoscopy. 2010; 22; 103-106.

2. Papanikolaou I. et al. Impaction of a gallstone into the duodenal wall. Endoscopy. 2010; 42; 297-298.

3. V. Bhatia, M. Tajika, and A. Rastogi. Upper gastrointestinal submucosal lesions – clinical and endosonographic evaluation and management. Tropical

Gastroenterology. 2010; 31; 5–29.

4. Izawa N. et al. Gastrointestinal stromal tumor presenting with prominent calcification. World Journal of Gastroenterology. 2012; 18; 5645–5648.

Susana Marques1, Joana Carmo1, Miguel Bispo 1, 2, Pedro Pinto Marques 2, David Serra 2

1 Department of Gastroenterology, Centro Hospitalar Lisboa Ocidental, Lisbon, Portugal

2 Department of Gastroenterology, Hospital da Luz, Lisbon, Portugal