Clinical classification of symptomatic heterotopic pancreas of the stomach and duodenum: A case series and systematic literature review

Abstract

Background: Heterotopic pancreas (HP) is an aberrant anatomic malformation that occurs most commonly in the upper gastrointestinal tract. While the majority of heterotopic pancreatic lesions are asymptomatic, many manifest severe clinical symptoms which require surgical or endoscopic intervention. Understanding of the clinical manifestations and symptoms of HP is limited due to the lack of large volume studies in the literature. The purpose of this study is to review symptomatic cases at a single center and compare these to a systematic review of the literature in order to characterize common clinical manifestations and treatment of this disease.

Aim: To classify the common clinical manifestations of heterotopic pancreas.

Methods: A retrospective review was conducted of pathologic samples containing heterotopic pancreas from 2000-2018. Review was limited to HP of the upper gastrointestinal tract due to the frequency of presentation in this location. Symptomatic patients were identified from review of the medical records and clinical symptoms were tabulated. These were compared to a systematic review of the literature utilizing PubMed and Embase searches for papers pertaining to heterotopic pancreas. Publications describing symptomatic presentation of HP were selected for review. Information including demographics, symptoms, presentation and treatment were compiled and analyzed.

Results: Twenty-nine patient were identified with HP at a single center, with six of these identified has having clinical symptoms. Clinical manifestations included, gastrointestinal bleeding, gastric ulceration with/without perforation, pancreatitis, and gastric outlet obstruction. Systemic review of the literature yielded 232 publications detailing symptomatic cases with only 20 studies describing ten or more patients. Single and multi-patient studies were combined to form a cohort of 934 symptomatic patients. The majority of patients presented with abdominal pain (67%) combined with one of the following clinical categories: (1) Dyspepsia, (n = 445, 48%); (2) Pancreatitis (n = 260, 28%); (3) Gastrointestinal bleeding (n = 80, 9%); and (4) Gastric outlet obstruction (n = 80, 9%). The majority of cases (n = 832, 90%) underwent surgical or endoscopic resection with 85% reporting resolution or improvement in their symptoms.

Conclusion: Heterotopic pancreas can cause significant clinical symptoms in the upper gastrointestinal tract. Better understanding and classification of this disease may result in more accurate identification and treatment of this malformation.

Keywords: Aberrant pancreas; Ectopic pancreas; Groove pancreatitis; Heterotopic pancreas; Pancreatic rest.

Figure 1

Image demonstrating the gastric antrum with an intramural mass identified within the wall of the stomach.

Figure 2

Histopathologic images. A: Histologic appearance of heterotopic pancreas in the stomach; B: High power view of heterotopic pancreas demonstrating pancreatic acinar and ductal architecture.

Figure 3

Coronal (A), axial (B), and (C) sagittal images of the abdomen and pelvis following the administration of IV contrast demonstrates enhancing heterotopic pancreatic tissue within the wall of the stomach along the lesser curvature (white arrows). The heterotopic pancreatic tissue is intramural in location and demonstrates similar attenuation characteristics of the adjacent pancreatic tissue seen on the coronal and sagittal images (white arrowhead).

Figure 4

Computed tomography images. A: Axial image demonstrating heterotopic pancreatic tissue within the stomach (white arrow). B: Axial image demonstrating heterotopic pancreas (white arrow) with associated psudocyst (white arrowhead). C: Coronal reformatted image demonstrating heterotopic pancreas tissue (white arrow) with associated pseudocyst (arrowhead) causing gastric outlet obstruction.

Figure 5

Non-contrast axial T1 weighted (A), coronal T2 weighted (B), and coronal postcontrast T1 weighted (C) images show a lesion within the first portion of the duodenum (white arrow) demonstrating T1 pre-contrast hyperintense signal similar to that of the adjacent pancreas (white arrowhead). This tissue shows similar imaging characteristics of the adjacent pancreatic tissue on the T2 coronal and T1 coronal post contrast images.

Figure 6

Single spot image of the stomach on a barium fluoroscopic study demonstrates an intraluminal filling defect within the stomach with a central indentation (arrow) consistent with pancreatic heterotopia.