Description:
A 54 year old female underwent upper endoscopy at an outside facility for evaluation of dyspepsia showing a subepithelial gastric mass. Mucosal biopsies were non-diagnostic. The patient was referred to our center for endoscopic ultrasound and further tissue sampling.
Upper endoscopy showed a 1 cm subepithelial mass in the gastric antrum located approximately 3 cm from the pylorus in the 6 o'clock endoscopic position. The lesion displayed central umbilication which is a characteristic feature present in the majority of pancreatic rests.
Pancreatic rests are benign congenital anomalies present in up to 3% of the population. Although they can be found anywhere along the GI tract, they are most commonly located in the gastric antrum.
The majority of pancreatic rests are asymptomatic and found incidentally at the time of routine endoscopy. Rarely patients can present with upper gastrointestinal bleeding, dyspepsia, ectopic pancreatitis, gastric outlet obstruction, and even malignant degeneration.
The differential diagnosis of any gastric subepithelial mass includes benign entities such as pancreatic rests, lipomas, inflammatory polyps, hyperplastic mucosa, and cysts as well as entities with malignant potential such as carcinoid tumors and gastrointestinal stromal tumors. Endoscopic ultrasound can be helpful in further characterizing a suspected pancreatic rest.
Our patient underwent endoscopic ultrasound, which showed an oval, hypoechoic, heterogeneous lesion located in the submucosal layer with intact overlying mucosa consistent with a pancreatic rest.
Tissue sampling of pancreatic rests using standard techniques is often non-diagnostic due to inadequate depth of sampling; therefore this suspected pancreatic rest was removed using band ligation snare polypectomy.
The endoscope fitted with a band ligation cap was placed over the lesion. Suction was applied to aspirate the lesion into the cap and a band was deployed to ligate the lesion. A hexagonal snare was passed through the working channel of the endoscope. The snare was opened, placed over the polypoid ligated lesion, and tightened around the base. Electrocautery was applied and the snare was moved gently back and forth until polypectomy was completed. The lesion was suctioned into the cap and removed through the mouth. The scope was reinserted to examine the defect. In order to minimize the risk of bleeding, endoscopic clips were placed to close the defect. The resected specimen measured a little over 1 cm in diameter. Low power view of the lesion revealed pancreatic lobules located in the submucosa and a central ductal structure traveling upwards towards the mucosal surface giving the pancreatic rest its characteristic umbilicated appearance. Higher power view again demonstrated pancreatic lobules and a hypertrophied ductal structure which are diagnostic of pancreatic rests.
In summary, pancreatic rests are benign congenital anomalies most often found incidentally during routine upper endoscopy. On endoscopy they appear as subepithelial lesions, approximately 1 cm in diameter, located in the gastric antrum a few centimeters from the pylorus in the 3-7 o'clock position. The majority display central umbilication. Given their benign nature, asymptomatic lesions with characteristic endoscopic and endosonographic features of pancreatic rests can be left alone. However, if the lesion is symptomatic or atypical in appearance a tissue diagnosis can easily be obtained with band ligation snare polypectomy.
References:
1) Bain AJ, Owens DJ, Tang RS, et al. Pancreatic rest resection using band ligation snare polypectomy. Dig Dis Sci. 2011 Jun;56(6):1884-8
2) Chen SH, Huang WH, Feng CL, et al. Clinical analysis of ectopic pancreas with endoscopic ultrasonography: an experience in a medical center. J Gastrointest Surg. 2008;12:877-881
3) Rubbia-Brandt L, Huber O, Hadengue A, et al. An unusual case of gastric heterotopic pancreas. JOP. 2004;5:484-487
Contributed By:
Andrew J. Bain, MD, University of California San Diego
Suresh Pola, MD, University of California San Diego, Veterans Affairs San Diego Medical Center
Thomas Savides, MD, University of California San Diego
