Heterotopic Pancreas of the Gastrointestinal Tract and Associated Precursor and Cancerous Lesions: Systematic Pathologic Studies of 165 Cases

Endoscopic Mucosal Resection of Pancreatic Rest Presenting as a Sub-epithelial Nodule in the Gastric Antrum

Pancreatic rest/ectopic pancreas is a rare condition. An 82-year-old male presented with abdominal pain and was found to have an antral nodule on esophagogastroduodenoscopy (EGD). An endoscopic ultrasound (EUS) was done and the nodule was resected. Histology showed ectopic pancreatic tissue with pancreatic intraepithelial neoplasia, PanIN-1 (low-grade dysplasia). This case highlights the importance of considering pancreatic rest as a differential in patients who present with a gastric sub-epithelial lesion and the associated finding of PanIN-1 highlights the importance of resecting such heterogeneous appearing lesions given the potential risk of progressing to pancreatic ductal adenocarcinoma (PDA).

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

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.

Granulocytic epithelial lesion (GEL) in heterotopic pancreas

BACKGROUND

The diagnosis of type 2 autoimmune pancreatitis (AIP) is dependent on typical radiologic imaging and the presence of the granulocytic epithelial lesion (GEL), which is characterized by ductal neutrophilic infiltration with or without neutrophilic acinar infiltration.

METHODS

We evaluated GEL and related clinicopathologic factors in 165 resected heterotopic pancreata (HPs) [57 gastric (35%), 56 duodenal (34%), 30 omental (18%), and 22 jejunal (13%)] and 29 matched orthotopic pancreata routinely examined during surgery.

RESULTS

GEL was noted in 8% (13/165) of HPs, including ductal epithelial (6/13, 46%) and intraluminal (8/13, 62%) neutrophilic infiltrations. However, there was no GEL in orthotopic pancreata. Abdominal pain was observed in 6 (46%) patients with GEL-positive HPs. GEL was more commonly observed in HPs having symptoms (p = 0.029), a larger size (p = 0.028), and an infiltrative growth pattern (p = 0.006). In addition, periductal lymphoplasmacytic infiltration and fibrosis (both p < 0.001), interstitial fibrosis (p = 0.017), acinar neutrophilic infiltration (p = 0.032), venulitis (p = 0.050), acinar ductal metaplasia (ADM; p = 0.040), and pancreatic intraepithelial neoplasia/intraductal papillary mucinous neoplasms (PanIN/IPMN; p < 0.001) were more commonly seen in HPs with GEL than in those without GEL. Inflammatory bowel disease was present only in one patient with GEL-negative HP.

CONCLUSIONS

GELs are detected in a subset of HPs without clinical evidence of AIP. Therefore, for the diagnosis of AIP, GEL should be carefully interpreted with the context of other histologic, clinical, and radiologic findings.

Evaluation and management of a pancreatic rest noted during pre-bariatric surgery screening endoscopy

INTRODUCTION

Pancreatic rest (PR) is an ectopic pancreatic lesion that is usually found incidentally on endoscopy or surgery. While most lesions do not have clinical significance, some patients are symptomatic and rarely, PR can predispose to malignancy. With the growing popularity of bariatric surgery, it has been unclear how to manage PR found on screening endoscopies, prior to bariatric surgery. Through review of the current literature, we propose an algorithm for clinicians to evaluate and manage PR found on screening endoscopies prior to bariatric surgery.

METHODS

We performed a literature search in PubMed pertaining to PR, clinical characteristics, risk of malignant transformation, endoscopic characteristics, histological descriptions, and resection techniques. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), we found 33 published articles from 2001 to 2019, including case reports, case series, retrospective cohorts, and a review paper.

RESULTS

PR is commonly found incidentally in the gastric antrum. Larger lesions have a higher risk of being symptomatic or predisposing to malignant transformation. Endoscopic ultrasound (EUS) can assist in the diagnosis of PR and guide resection technique. Certain histological characteristics, such as Heinrich class, grading of neoplasia, and genetic alterations, can determine malignancy risk of PR. Resection technique, either endoscopically or surgically, should be based on lesion size, depth of wall invasion, and the endoscopists' level of skill in endoscopic resection.

CONCLUSIONS

Proper evaluation and treatment of PR should be considered because of the risk for symptoms and malignant transformation. Symptomatic lesions and those at risk for malignant transformation should be considered for resection. EUS can guide the diagnosis and type of resection, either endoscopically through EMR or ESD or surgically through sleeve gastrectomy or Roux-en-Y gastric bypass (RYGB).

Adenocarcinoma with intraductal papillary mucinous neoplasm arising in a duodenal heterotopic pancreas: a case report

A woman in her 70 s was diagnosed with a tumor in her duodenal wall during a routine visit for diabetes. She subsequently underwent subtotal stomach-preserving pancreatoduodenectomy. Histologically, the tumor was present mainly in the duodenal wall, and atypical cystic ducts were seen in the muscularis propria and subserosa. Invasive well-differentiated adenocarcinoma was seen in the duodenal submucosal and mucosal layers. Heterotopic pancreatic tissue was seen within the tumor, and atypical epithelium had proliferated and replaced the cystic ductal epithelium of the heterotopic pancreas. Therefore, adenocarcinoma with intraductal papillary mucinous neoplasm arising in duodenal heterotopic pancreas was the final histopathological diagnosis, which is considered rare.

The malignancy among gastric submucosal tumor

The origin and characteristics of most submucosal tumors (SMTs) cannot easily be confirmed by gastrointestinal endoscopy or other radiological examinations. Excluding GISTs, for those other gastric SMTs, most of which are deemed benign, the necessity and timing of intervention has been ignored. Thus, the malignancy of gastric SMTs still remains unknown. In order to summarize the malignancy of these gastric SMTs, we reviewed literatures and analyzed cases of gastric SMTs including heterotopic pancreas, leiomyoma, schwannoma, glomus tumor, hemangioendothelioma, granular cell tumor (GCT), lipoma, hemangiopericytoma, lymphangioma and neurofibroma. In these literatures, there are cases of malignancy among heterotopic pancreas, leiomyoma, schwannoma, glomus tumor, hemangioendothelioma and GCT. As a result, it suggests that although most of gastric SMTs are considered benign, there are still possibilities of malignancy, which requires our attention, even active intervention and long-term follow-up.

A unique case of ectopic pancreas presenting as jejunal malignance

Ectopic pancreas is defined as pancreatic tissues having no anatomic or vascular connections with the orthotopic pancreas. It is difficult for clinicians to diagnose this disease without performing a histopathological examination because it lacks specific clinical manifestations. This case report is of a 46-year-old woman who presented with epigastric pain. She had elevated serum levels of carcinoembryonic antigen (CEA) and carbohydrate antigen 72-4 (CA72-4). Abdominal contrast-enhanced computed tomography (CT) revealed a persistently enhanced mass in the proximal jejunum, which was confirmed as ectopic pancreas via histopathological examination. Her serum CEA and CA72-4 levels were restored to normal ranges after resecting the jejunal ectopic pancreas. This is the first reported case of ectopic pancreas causing an elevation in serum CEA and CA-724 levels; this report supports the metaplasia theory and suggests that jejunal masses should be cautiously diagnosed for avoiding unnecessary concerns among patients and their families.

Duodenal Epithelial Polyps: A Clinicopathologic Review

CONTEXT.—

Duodenal epithelial polyps are reported in 1.5% to 3% of individuals referred for upper endoscopy. Most duodenal epithelial polyps are asymptomatic and nonneoplastic; however, a small subset is neoplastic and may progress to adenocarcinoma. Recent advances in immunohistochemical and molecular techniques have helped further characterize these polyps, shedding light on their origin, classification, and risk of progression to adenocarcinoma.

OBJECTIVE.—

To provide a comprehensive clinicopathologic review of nonneoplastic and neoplastic duodenal epithelial polyps, with particular emphasis on recent developments in classification schemes and risk stratification based upon immunohistochemical and molecular profiles.

DATA SOURCES.—

This review is based on peer-reviewed literature and the authors' experiences.

CONCLUSIONS.—

In this review we provide an update on the clinicopathologic, immunohistochemical, and molecular features of duodenal epithelial polyps and discuss the surveillance recommendations and treatment options available. Particular attention should be placed on recognizing duodenal adenomas with intestinal, gastric, and serrated phenotype, as they have an increased risk of malignant transformation if not completely excised.

Pancreatic intraepithelial neoplasia in heterotopic pancreas: incidentally diagnosed on endoscopic mucosal resection of a duodenal polyp

Heterotopic pancreas is the presence of pancreatic tissue outside its normal location. It can develop similar pathological conditions that develop in the normal pancreas, including adenocarcinoma and its precursor lesions. Due to the rarity of the condition, the diagnosis can be challenging, and treatment is not well established. ​We present a 47-year-old female patient referred for endoscopic resection of a 2 cm polyp in the second part of her duodenum. Complete endoscopic mucosal resection (EMR) was performed, with pathology revealing low-grade pancreatic intraepithelial neoplasia (PanIN) in heterotopic pancreatic tissue. To the best of our knowledge, this is the first case of heterotopic pancreas with low-grade PanIN in the duodenum to be incidentally diagnosed and treated with EMR.