Intraductal papillary mucinous neoplasm originating from a jejunal heterotopic pancreas: report of a case. Surg Today. 2014;44:349-353. [PMID: 23325495 DOI: 10.1007/s00595-012-0486-0]

Intraductal Papillary Mucinous Neoplasm Arising from Heterotopic Pancreas in Stomach: A Case Report and Review of Literature

Heterotopic pancreas is generally an asymptomatic condition which is found incidentally at surgery, endoscopy, or autopsy. Intraductal papillary mucinous neoplasm (IPMN) arising from heterotopic pancreas is extremely rare. In this study, we report a patient with IPMN arising from heterotopic pancreas. A 28-year-old man presented to our department with epigastric pain for 20 days. Physical examination revealed no abnormal findings. Computed tomography (CT) revealed an intramural cystic-solid mass on the gastric wall. Endoscopic ultrasonography (EUS) revealed a hypoechoic, heterogeneous, and multilobulated lesion with septa. Cyst fluid analysis based on EUS guided fine needle aspiration (EUS-FNA) indicated that the concentration of carcinoembryonic antigen (CEA) was 492 ng/ml. The patient received Billroth I subtotal gastrectomy, and then a 4.6 cm mass from the lesser curvature of the stomach was removed. Finally, the patient was diagnosed as IPMN with low grade dysplasia in an ectopic pancreas based on histopathological analysis. This report described the clinical, radiologic, endoscopic and histologic features of IPMN arising from heterotopic pancreas in a 28-year-old man involving the stomach. All pathologists involved in the diagnosis and clinicians involved in the treatment should be aware of this kind of tumor pattern to improve the correct identification, diagnosis and management of patients.

L., Jayaprakash Shetty K., Shreesha Khandige. Asymptomatic pancreatic heterotopia in an incidental Meckel's diverticulum – A rare case report

Pancreatic heterotopia is a rare, unusual finding where pancreatic tissues are found out of the normal anatomical location. Various studies have documented an incidence of 0.5 to 13% in autopsy. The reports on pancreatic heterotopia presence is rare, with an incidence estimated to be around 0.2% of all upper gastrointestinal surgeries. The heterotopic pancreas occurs frequnetly in the stomach, duodenum and proximal jejunum. Remote cases of  pancreatic heterotopia in Meckel's diverticulum is a rare finding. These heterotopias are  often clinically silent and are an  incidental findings  upon pathological examination or autopsy.

Clinicopathological features of intraductal papillary mucinous neoplasm derived from ectopic pancreas: A systematic review

Background

Methods

Results

Conclusion

•

The ectopic pancreas can be complicated with pancreatitis, pseudocyst formation, cyst formation, insulinoma, adenoma, and malignant transformation. Intraductal papillary mucinous neoplasm (IPMN) derived from the ectopic pancreas is rare and can undergo malignant transformation.

•

It is challenging to diagnose IPMN derived from ectopic pancreas preoperatively using the existing imaging modalities. Moreover, the clinicopathological characteristics of these tumors have not been elucidated.

•

We performed a review of case reports on IPMNs derived from the ectopic pancreas, including intraductal papillary mucinous carcinoma (IPMC) that was treated in our hospital, to determine the clinicopathological features of the tumors.

•

This is the first systematic review of the literature on IPMN derived from the ectopic pancreas. The review revealed that IPMN derived from the ectopic pancreas was diagnosed incidentally in most patients, and some patients were asymptomatic.

•

The existing imaging modalities may not accurately diagnose the condition preoperatively and differentiate between IPMN and IPMC. Risk factors for malignant transformation should be clarified through further research.

A case of ectopic pancreas of the stomach accompanied by intraductal papillary mucinous neoplasm with GNAS mutation

BACKGROUND

Ectopic pancreas is basically a benign disease and is not always necessary to be removed. However, all types of neoplasms occurring in the normal pancreas such as ductal adenocarcinomas and intraductal papillary mucinous neoplasms (IPMNs) may develop even within ectopic pancreas. We recently encountered an extremely rare case of ectopic pancreas in the gastric antrum associated with IPMN possessing a GNAS mutation.

CASE PRESENTATION

A 71-year-old Japanese woman complained of epigastric pain. Computed tomography and upper gastrointestinal endoscopy showed an intramural cystic mass in the antrum of the stomach. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) biopsy did not give a definitive diagnosis, and the patient underwent resection of the lesion. Histology of the resected specimen showed that the gastric intramural lesion was ectopic pancreas. Moreover, the lesion contained dilated duct components with tubulo-villous epithelial proliferation consistent with pancreatic IPMN. Since the covering epithelial cells had highly atypical nuclei, the lesion was diagnosed as IPMN with high grade dysplasia. Immunohistochemistry showed that the IPMN component showed to be MUC2-, MUC5AC-, and CDX2-positive but MUC1- and MUC6-negative. Mutational analyses using genomic DNA revealed that the IPMN component had a mutation of GNAS at exon 8 (Arg201Cys).

CONCLUSION

We finally diagnosed this case as gastric ectopic pancreas accompanied by intestinal type IPMN with high grade dysplasia possessing GNAS mutation. Although there were 17 cases of ectopic pancreas with IPMN including 6 cases of gastric ones reported in the English literature, this is the first case of ectopic pancreas with IPMN which was proved to have GNAS mutation. Intimate preoperative examinations including imaging analyses and EUS-FNA biopsy/cytology are recommended to decide whether the lesion has to be resected or not even if they are not effective for getting the right diagnosis.

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.

A case report and literature review: incidental jejunal ectopic pancreatic tissue in an emergency bowel exploration for suspected intussusception

Heterotopic pancreas (HP) is defined as pancreatic tissue which is an anatomically separate entity from the main pancreas and free from the organ's vascular or ductal continuity. Most cases of HP are asymptomatic and are diagnosed incidentally upon laparotomy or on autopsy. The diagnosis of HP can be extremely difficult. A few imaging modalities which include Magnetic resonance imaging (MRI) and magnetic resonance cholangiopancreatography (MRCP) may show characteristic features of HP. However, definitive diagnosis is made by histopathology. Conversely, these modalities may not differentiate a malignant neoplasm from a benign mass. Surgical excision is thought to be curative for HP. In this case report, we present a 62-year-old female with acute myelocytic leukemia on induction chemotherapy who developed abdominal pain during her hospital admission and was referred to the general surgery department. Abdominal computed tomography (CT) was done and showed signs of small bowel obstruction, perforation, and overlapping jejunoileal segments suggestive of intussusception. Upon surgical exploration two small bowel perforations were repaired, one iatrogenic and one pathological. On bowel run a jejunal mass was found, excised, and upon histopathology confirmed to be a mixed endocrine and exocrine heterotopic pancreatic choristoma. Definitive diagnosis of heterotopic pancreatic tissue is made by histopathology, and surgical excision is potentially curative. In conclusion, we recommend excising HP if found incidentally upon surgery as the diagnosis of HP and exclusion of neoplasm may not be possible without a histological specimen.

Pancreatic and Gastric Heterotopia in the Gallbladder: A Rare Incidental Finding

Heterotopic or ectopic tissue is a congenital anomaly, which is defined as the presence of the tissue outside its normal location, without neural, vascular, or anatomic connection with the main body of an organ in which it normally exists. This tissue is usually discovered incidentally and may be asymptomatic or may present with nonspecific gastrointestinal (GI) symptoms. Pancreatic and gastric heterotopia are the two predominantly occurring heterotopic tissues in the GI tract.[12] The prevalence of ectopic pancreatic tissue in the GI tract ranges from 0.6% to 13.7% of autopsy series and it can be present anywhere in the GI tract with the most common localizations being stomach (27.5%), duodenum (25.5%), colon (15.9%), esophagus, and Meckel's diverticulum.[345] It is a rare finding in the gallbladder and its prevalence has not been ascertained due to lack of large-scale studies and systematic review of literature. Similarly, heterotopic gastric tissue is common throughout the GI tract from the tongue to the rectum,[67] but it is extremely rare in the gallbladder with only around 34 cases reported in literature so far, while other cases of different types of heterotopic tissues in the gallbladder such as liver tissue and others such as adrenal and thyroid tissues have been described.[8] The most common presentation of ectopic tissue in the gallbladder is colicky pain in the epigastrium or right upper quadrant sometimes associated with nausea and vomiting. Here, we are presenting two incidentally detected cases, each of gastric and pancreatic heterotopias in the gallbladder.

Intraductal papillary mucinous neoplasm originating from a heterotopic pancreas within the jejunum: a case report

We report a case of intraductal papillary mucinous neoplasm arising within the heterotopic pancreatic tissue which was found incidentally in the jejunum during surgery for bowel obstruction. A 54-year-old female patient was admitted to our hospital due to sudden abdominal pain. In preoperative findings, we diagnosed bowel obstruction and performed surgery. Intra-operative findings showed adhesive intestinal obstruction, we performed synechiotomy for adhesion release. During surgery, when searching the small intestine, we coincidentally found a tumor in the jejunum and partial resected the jejunum. Pathological examination revealed a 1.2 cm × 1.0 cm × 1.0 cm white yellow nodule with cystic spaces. Histological examination demonstrated heterotopic pancreatic tissue consisting of well-formed lobules of pancreatic acini and cystically dilated ducts containing intraductal papillary neoplasm. Moreover, in immunohistochemical staining, MUC5AC was diffusely expressed, but not MUC1, MUC2 and MUC6.

Ectopic Pancreatic Tissue Adherent to the External Gallbladder Wall

Heterotopic pancreatic tissue can be found in the gastrointestinal tract, with the stomach and small bowel being the most common sites of localization. The gallbladder is seldom affected. Here, we report 2 cases of ectopic pancreas within the fatty tissue adherent to the organ wall. Both cases concerned young women (31 and 36 years old) who were treated with a laparoscopic cholecystectomy due to persistent abdominal symptoms thought to be related to chronic cholecystitis. Pathological examination revealed the presence of ectopic pancreatic tissue type 1.

Ectopic pancreas in the upper gastrointestinal tract: Is endosonographic diagnosis reliable? Data from the German Endoscopic Ultrasound Registry and review of the literature

Background:

Ectopic pancreas (EP) belongs to the most frequent subepithelial lesions (SELs) of the upper gastrointestinal (GI) tract. In the majority of cases, it is detected incidentally. Differential diagnosis from mesenchymal subepithelial tumors may be difficult.

Methods:

Among 24,308 endosonographic examinations and interventions, which were prospectively enrolled in the database of the German Endoscopic Ultrasound (EUS) Registry from January 2009 to August 2013, 575 were performed for suspected SELs of the upper GI tract. Sixty three cases of EP of the upper GI tract (stomach, n = 53; duodenum, n = 10; esophagus, n = 0) were extracted and retrospectively reviewed.

Results:

In 65.1% of cases, radial echoendoscopes or radial miniprobes were used for examination. Nearly 84% of EP was found in the stomach, 16% in the duodenum, none in the esophagus. In 88.9% of cases, the EUS examination discerned the layer of origin. In 59% of cases EP was described as a heterogeneous, in 28.6% as a homogeneous-hypoechoic and in 7.9% as a homogeneous-echogenic subepithelial mass lesion. Mean diameter was 13.0 mm × 8.1 mm, the mean ratio between long and short axis diameter was 1.75. EUS-guided fine needle aspiration (EUS-FNA) was used to accomplish cytological or histological diagnosis in only 6.3% of cases.

Conclusions:

EP accounts for 11% of all EUS examinations performed for subepithelial lesions of the upper GI tract and prospectively enrolled in the German EUS registry. Rather than being an eyecatcher, EP is a chameleon with numerous differential diagnoses. In selected cases, EUS-FNA may help clarifying the diagnosis.

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

Heterotopic pancreas (HP) can be detected by accompanying symptoms or incidentally during gastrointestinal (GI) tract tumor resection. We compared clinicopathologic features among 165 resected HPs (57 gastric [35%], 56 duodenal [34%], 30 omental [18%], and 22 jejunal [13%]). Symptomatic HPs (79/135 GI tract wall HPs, 59%) were larger (P=0.05), more common in younger patients and in a gastric location (both P<0.001), and more frequently associated with lymphoid cuffs (P=0.03) than incidentally found HPs. Gastric/jejunal HPs were more frequently symptomatic (P<0.001), deeply located (P=0.03), and associated with lymphoid cuffs (P=0.008) and pancreatic intraepithelial neoplasia/intraductal papillary mucinous neoplasms (PanIN/IPMN; P=0.001) than duodenal HPs. HP was frequently associated with acinar-ductal metaplasias (117/135 GI tract wall HPs, 87%) and PanINs/IPMNs (68/135, 50%); those with PanINs/IPMNs were larger (P<0.001), more frequently located in stomach (P=0.001), had deeper wall involvement (P=0.03), and more often showed infiltrative growth (P<0.001) and lymphoid cuffs (P=0.02). Four HPs containing PanINs abutted adenocarcinomas, all expressing wild-type KRAS and intact SMAD4/DPC4 expression. Thus, symptomatic HP is associated with younger age, larger size, gastric location, and lymphoid cuffs. HPs containing PanINs/IPMNs (usually low grade) are larger and more common in stomach, have deeper wall location, and show infiltrative growth and lymphoid cuffs. Adenocarcinomas are rarely observed adjacent to HPs with PanINs/IPMNs. KRAS mutational and SMAD4/DPC4 immunohistochemical studies can discriminate between adenocarcinoma derived from HP and concurrent adenocarcinoma with HP.

The Role of Laparoscopy in the Management of a Diagnostic Dilemma: Jejunal Ectopic Pancreas Developing into Jejunojejunal Intussusception

Ectopic pancreas (EP) is a rare congenital anomaly defined as the presence of pancreatic tissue in topographic anomaly. It is usually silent but it may become clinically evident when complicated by acute conditions. The development of laparoscopic surgery has changed the way to manage such conditions, especially in the setting of emergency surgery, thanks to its diagnostic and therapeutic role with excellent results. We decided to perform an emergency diagnostic exploratory laparoscopy in a 29-year-old man with an acute abdomen and nonspecific radiological images for intestinal occlusion. A jejunojejunal intussusception was found, caused by a mass. We decided to carry out minilaparotomy to perform a resection of the affected jejunum. Histological examination confirmed the presence of a jejunal ectopic pancreas. Adult intussusception caused by EP represents 5% of all cases of intussusception. As CT scan, especially when performed in emergency setting for small bowel obstruction diagnosis, can usually demonstrate nondiagnostic findings suggestive of intussusception of unknown origin, laparoscopic exploration could help surgeons in order to perform a resolute diagnosis and treat the pathology.

Increased 18F-FDG uptake of heterotopic pancreatitis in the small intestine: A CARE-compliant case report

BACKGROUD

Heterotopic pancreas (HP), a relatively uncommon congenital anomaly, is rarely noted during F-FDG positron-emission tomography/computed tomography (PET/CT) scan.

METHODS

A 60-year-old woman was referred to our hospital due to a 10-day history of abdominal pain with elevated levels of serum amylase and lipase. Abdominal CT and ultrasound examinations were negative. In order to search for the cause, an F-FDG PET/CT whole body scan was suggested to an old woman revealing the presence of F-FDG accumulating nodule in small intestine.

RESULTS

Surgical findings and pathologic results confirmed the diagnosis of small intestinal heterotopic pancreas with active chronic inflammation.

CONCLUSION

This uncommon case underscores the necessity of considering heterotopic pancreatitis in small intestine with focal F-FDG uptake as a possible differential diagnosis in intestinal tumor and tuberculosis.

Mutational spectrum of intraepithelial neoplasia in pancreatic heterotopia

Heterotopic pancreatic parenchyma recapitulates the normal pancreas in extrapancreatic locations and, on rare occasions, can even give rise to pancreatic adenocarcinoma. The genetic signatures of pancreatic adenocarcinoma and its precursor lesions are well characterized. We explored the genetic alterations in precursor lesions (intraductal papillary mucinous neoplasms [IPMN], pancreatic intraepithelial neoplasia [PanIN]) in patients with pancreatic heterotopias but without concomitant pancreatic ductal adenocarcinomas. This allowed us to determine whether the stereotypical dysplasia--infiltrating carcinoma sequence also occurs in these extrapancreatic foci. Seven cases of heterotopic pancreas with ductal precursor lesions were identified. These included 2 IPMNs with focal high-grade dysplasia and 5 PanINs with low- to moderate-grade dysplasia (PanIN grades 1-2). Neoplastic epithelium was microdissected and genomic DNA was extracted. Sequencing of commonly mutated hotspots (KRAS, TP53, CDKN2A, SMAD4, BRAF, and GNAS) in pancreatic ductal adenocarcinoma and its precursor lesions was performed. Both IPMNs were found to have KRAS codon 12 mutations. The identification of KRAS mutations suggests a genetic pathway shared with IPMN of the pancreas. No mutations were identified in our heterotopic PanINs. One of the possible mechanisms for the development of dysplasia in these lesions is field effect. At the time of these resections, there was no clinical or pathologic evidence of a prior or concomitant pancreatic lesion. However, a clinically undetectable lesion is theoretically possible. Therefore, although a field effect cannot be excluded, there was no evidence for it in this study.

Intraductal papillary mucinous neoplasm of the ileal heterotopic pancreas in a patient with hereditary non-polyposis colorectal cancer: A case report

We report a case of intraductal papillary mucinous neoplasm (IPMN) originating from the ileal heterotopic pancreas in a patient with hereditary non-polyposis colorectal cancer (HNPCC). A 49-year-old woman had a past history of total colectomy and total hysterectomy with bilateral salpingo-oophorectomy due to colonic adenocarcinoma and endometrial adenocarcinoma 11 years ago. Her parents died from colonic adenocarcinoma and her sister died from colonic adenocarcinoma and endometrial adenocarcinoma. The clinician found an ileal mass with necrotic change and the mass increased in size from 1.7 cm to 2.2 cm during the past 2 years on computed tomography. It was surgically resected. Microscopically, the ileal mass showed heterotopic pancreas with IPMN high grade dysplasia. Immunohistochemical staining revealed positive reactivity for MLH1/PMS2 and negative reactivity for MSH2/MSH6. This is the first report of IPMN originating from the ileal heterotopic pancreas in a patient with HNPCC in the English literature.

Asymptomatic heterotopic pancreas in Meckel's diverticulum: a case report and review of the literature

Introduction

Heterotopic pancreas is defined as pancreatic tissue without a real anatomical or vascular connection to the pancreas. It can be found in the stomach, duodenum, jejunum, ileum, Meckel’s diverticulum, colon gall bladder, umbilicus, fallopian tube, mediastinum, spleen and liver. Complications of heterotopic pancreas are inflammation, bleeding, obstruction, malignant transformation, carcinoid syndrome, jejunojejunal intussusception and ileus, but it is usually asymptomatic and diagnosed only during examinations for other diseases.

Case presentation

An 81-year-old Lithuanian woman was diagnosed with caecal cancer and had undergone elective surgery. A right hemicolectomy was performed and a Meckel’s diverticulum was observed and excised. Histological results showed a poorly differentiated G3 adenocarcinoma of her large intestine and heterotopic pancreas tissue in the Meckel’s diverticulum and mesenteric adipose tissue.

Conclusions

Asymptomatic heterotopic pancreas is rarely diagnosed, and usually found incidentally during surgical or diagnostic interventions. Although it has no symptoms, heterotopic pancreas found during surgical procedures should be excised.

Heterotopic Pancreas within the Proximal Hepatic Duct, Containing Intraductal Papillary Mucinous Neoplasm

We report a unique first case of benign heterotopic pancreas arising within the proximal hepatic bile duct, containing a focus of intraductal papillary mucinous neoplasm (IPMN). The condition was diagnosed on pathological explant after left hepatic lobectomy with total extrahepatic bile duct excision.