Heterotopic Pancreas Presented as Duodenal Tumor with Obstruction

Abstract

Heterotopic pancreas (HP) is defined as pancreatic tissue lacking anatomic and vascular continuity with the main body of the pancreas. Most are asymptomatic, but can cause ulcer, bleeding, intussusception, and mechanical obstruction. Herein, we presented one case of HP presented as duodenal tumor causing duodenal obstruction. A 7-year-old girl visited the emergency room for abdominal pain with vomiting for 24 hours. Computed tomography and upper gastrointestinal series revealed a polypoid mass with short stalk in the 2nd portion of duodenum. We attempted an endoscopic removal. However, the lumen was nearly obstructed by the mass and the stalk was too broad and hard to excise. The mass was surgically removed via duodenotomy. It was confirmed as a HP with ductal and acini components (type 2 by Heinrich classification). Postoperatively, the patient has been well without any complication and recurrence.

Keywords: Duodenal neoplasms; Duodenal obstruction; Heterotopic pancreas; Pancreas.

Fig. 1. Simple abdomen revealed a 3 cm sized soft tissue density near the pylorus without small bowel obstruction (arrow).

Fig. 2. Computed tomography revealed a well demarcated mass near the ampulla of Vater in the 2nd portion of duodenum.

Fig. 3. Ultrasonography showed hyperechoic mass-like lesion with short stalk in the 2nd portion of duodenum.

Fig. 4. Upper gastrointestinal series revealed ovoid-shaped filling defect in the 2nd portion of duodenum.

Fig. 5. After Kocher's maneuver, we identified the mass and exposed it after duodenotomy. We identified the mass (A) and exposed it after duodenotomy (B).

Fig. 6. Under the microscope, nodular lesions were composed of variably dilated ductular mucinous and pancreatic exocrine acinar tissue (H&E; A: ×40, B: ×200). Acini tissue showed positive reaction to CK19 immunohistochemistry (C: ×40, D: ×200). It was confirmed as heterotopic pancreas, ductal and acini component (type 2 by Heinrich classification).