Adenocarcinoma arising in gastric heterotopic pancreas: clinicopathological and immunohistochemical study with genetic analysis of a case

Aberrant pancreas adenocarcinoma in the stomach: A case report and literature review

RATIONALE

Aberrant pancreatic tissue in the gastrointestinal tract is a relatively common finding. However, malignant transformation is extremely rare. Herein, we report a case of ectopic pancreatic ductal adenocarcinoma in the stomach wall.

PATIENT CONCERNS

A 38 year old male presented with nausea, bloating, abdominal distention and weight loss for 4 months.

DIAGNOSES

Endoscopy of upper gastrointestinal tract was performed twice with 2 months interval and a stenotic pyloric part was observed with a suspected submucosal lesion. It was sampled both times, however the pathology findings of the mucosal biopsies were unremarkable with no identifiable neoplastic structures. CT scan and MRI was performed and showed a thickened pyloric wall with a submucosal lesion 15 × 15 mm in diameter. Blood levels of tumor markers carcinoembrionic antigen and carbohydrate antigen 19-9 were within a normal range.

INTERVENTIONS

Pyloric stenosis progressed and the patient underwent a Billroth type I distal gastric resection with D2 lymphadenectomy. Pathologic examination revealed a well differentiated ductal adenocarcinoma arising in the heterotopic pancreatic tissue (Heinrich type III). The resection margins and lymph nodes were free of tumor. The patient received adjuvant chemotherapy with 6 courses of XELOX.

OUTCOMES

No disease recurrence is reported in 12 months follow-up.

LESSONS

Aberrant pancreatic ductal adenocarcinoma in the stomach is a rare finding, however this pathology should be included in the differential diagnosis of gastric submucosal lesion causing pyloric stenosis.

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.

Gastric Adenocarcinoma Arising from Heterotopic Pancreas Presenting as Gastric Outlet Obstruction 10 Years after the First Diagnosis

Gastric heterotopic pancreas is a relatively uncommon incidental finding. On the other hand, the presentation of gastric adenocarcinoma arising from a heterotopic pancreas is rare. This paper reports a case of gastric adenocarcinoma arising from a heterotopic pancreas that presented as a gastric outlet obstruction 10 years after the initial diagnosis of a suspicious submucosal tumor. Endoscopy revealed a pyloric stricture with prepyloric wall thickening and a complete gastric outlet obstruction. Abdominal and pelvic computed tomography exposed a severely distended gastric lumen at the antrum with heterogeneously enhancing circumferential wall thickening in the prepyloric antrum and pylorus. Because conservative treatment was ineffective and a malignancy could not be excluded, laparoscopic subtotal gastrectomy with a gastrojejunostomy was performed for histological confirmation and treatment. The histopathology diagnosis was advanced gastric carcinoma arising from heterotopic pancreatic tissue.

Heterotopic pancreas adenocarcinoma in the stomach: A case report and literature review

BACKGROUND

Heterotopic pancreas is a common lesion found in the gastrointestinal tract and is usually considered a benign disease. Reports of malignant change of heterotopic pancreas are scarce.

CASE SUMMARY

A 44-year-old Chinese female underwent a gastroscopy to assess abdominal distension that had persisted for 2 months. A protruding lesion in the gastric antrum was revealed but no malignant tissue was found in the biopsy specimen. The patient's symptom persisted and progressed to repeated vomiting. Endoscopy after 4 months revealed obstruction of the gastric outlet caused by the protruding lesion. A distal gastrectomy was performed. Histopathological examination of the surgical specimen showed the malignant transformation of aberrant pancreas in the stomach. Chemotherapy consisting of folinic acid, fluorouracil, and oxaliplatin was administered for three cycles, and was changed to gemcitabine monotherapy because of adverse effects and increased serum tumor marker levels. The patient remained asymptomatic during a 12-month follow-up.

CONCLUSION

Pancreatic heterotopy should be considered as source of a potentially malignant lesion, and early treatment or close monitoring for aberrant pancreas is recommended.

Rare gastric outlet obstruction owing to ectopic pancreas: a case report and literature review

The ectopic pancreas is often observed in the gastrointestinal tract, and is typically asymptomatic. A 28-year-old woman was referred to our hospital following repeated vomiting after every meal. Following gastroscopy, contrast-enhanced computed tomography (CE-CT), and endoscopic ultrasonography (EUS), she was diagnosed with gastric outlet obstruction, also known as pyloric obstruction, caused by a giant submucosal cystic tumor. The condition was successfully treated with EUS-guided cystic drainage, and she was diagnosed with a cystic tumor originating from the ectopic pancreas. The tumor shrank following EUS-guided cystic drainage, and her obstructive symptoms resolved. In cases with overgrowth of the ectopic pancreas, the differential diagnosis of malignancy is important but challenging. Herein, we report a unique final pathology of this rare case and discuss the findings with a literature review.

Ectopic pancreatitis in the antral stomach causing gastric outlet obstruction: a case of successful resection

Ectopic pancreas is a congenital developmental anomaly that may be caused by embryologic errors. The pathogenetic details of ectopic pancreas remain unclear, but it has gradually been determined to originate at the gene level. DNA errors during embryological development cause ectopic pancreas. Ectopic pancreas is generally asymptomatic and harmless throughout the patient's entire life; in very rare cases, however, it can be symptomatic and harmful, causing pain, fever, bleeding, and other adverse effects. We herein report an unusual case involving a 52-year-old Japanese woman who presented with nausea and vomiting due to inflammation of an ectopic pancreas in the gastric antrum. Ectopic pancreatitis caused severe pyloric stenosis, and she was unable to ingest food or water even after admission to the internal medicine ward. Ectopic pancreatitis is a very rare clinical condition, but clinicians should be cautious of this uncommon disease in patients who develop gastric outlet obstruction without cancer or ulcers. The present case report is clinically significant because surgical treatment (distal partial gastrectomy) relieved the patient's serious distress rapidly and successfully after unsuccessful conservative treatments for acute ectopic pancreatitis. Antrectomy (distal partial gastrectomy) might be useful for ectopic pancreas, especially in case of gastric outlet obstruction due to the ectopic pancreatitis.

A case report of esophageal heterotopic pancreas presenting as recurrent mediastinal abscess, treated by minimally invasive esophagectomy

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Heterotopic pancreas is a rare congenital anomaly.

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Patients may present with complications such as inflammation and abscess.

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The management depends on size, ability to exclude other etiologies and symptoms.

Introduction

Heterotopic pancreas is a rare congenital anomaly. We report a case of esophageal heterotopic pancreas complicated by recurrent mediastinal abscess and treated by minimally invasive resection.

Presentation of case

A 31-year-old woman was admitted with a history of recurrent chest pain, dysphagia, and heartburn. CT scan revealed focal confined collection in the lower mediastinum surrounding esophagus. Endoscopic ultrasound revealed a subepithelial lesion. The patient was treated by minimally invasive esophagectomy and made an uneventful postoperative recovery.

Discussion

The management of subepithelial lesions would depend on their size, ability to exclude other etiologies and their associated symptoms. The patient, in this case, was obviously symptomatic and accurate differentiation from malignant etiologies could not be accurately made.

Conclusion

Although pancreatic heterotopia is rare, it should be remembered in the differential diagnosis of various gastrointestinal lesions.

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.

Malignant Transformation of Ectopic Pancreas

Malignant transformation of ectopic pancreas tissue is a diagnostic challenge as clinical symptoms and radiographic features of these tumors are non-specific. Given the rarity of these lesions, it is usually neither suspected nor included in the diagnostic workup of different tumors. We conducted a comprehensive literature review regarding malignancy arising from ectopic pancreas for a better understanding of its frequency, clinicopathological features, and prognosis. A literature search was performed in three major databases: PubMed, Cochrane, and Web of Science. Fifty-four well-documented cases of malignant ectopic pancreas were identified in the published literature. Our analysis provided the following observations: (1) there was a slight predominance of males over females; (2) most patients with malignant transformation of ectopic pancreas were middle-aged; (3) most commonly, the tumor was located in the stomach; (4) most tumors were adenocarcinomas; (5) most frequently, the malignancy arose within a type I heterotopia according to Heinrich classification; (6) macroscopically, a subepithelial-like appearance was most frequently observed; and (7) improved prognosis for ectopic pancreatic malignancies in comparison with reported survival data for orthotopic pancreatic cancer. Even if the majority of cases of ectopic pancreas are incidental findings and malignant transformation is a rare event, pancreatic heterotopy should be considered as a source of potentially malignant lesions.

Acute Clinical Manifestation of Mesenteric Heterotopic Pancreatitis: A Pre- and Postoperative Confirmed Case

Heterotopic pancreas is a relatively uncommon congenital anomaly, defined as pancreatic tissue in ectopic sites without an anatomic and vascular continuity with the main body of the pancreas. We report the case of a 58-year-old woman who was admitted to the hospital with the clinical suspicion of a mild, acute pancreatitis. Computed tomography, magnetic resonance imaging, transabdominal ultrasound, and endoscopic ultrasound revealed a normal orthotopic pancreas and the suspicion of a large heterotopic pancreas in the small bowel mesentery with signs of acute inflammation. The diagnosis of mesenteric heterotopic pancreatitis was preoperatively confirmed by endoscopic ultrasound-guided fine-needle aspiration and consequently histologically established after surgical resection.

Gastric neuroendocrine tumor arising from heterotopic pancreas

There are few English reports on secondary tumors from heterotopic pancreas. Here, we describe a case of gastric neuroendocrine tumor (NET) arising from heterotopic pancreas. A 72-year-old woman underwent esophagogastroduodenoscopy as part of a general health check-up. An endoscopic examination revealed a submucosal tumor on the greater curvature of the gastric body. Laparoscopic and endoscopic cooperative surgery was performed. Histological diagnosis concluded that it was a Grade 1 NET arising from heterotopic pancreas. We report this extremely rare case of a NET presenting as a submucosal tumor, considered to have originated from heterotopic pancreatic tissue.

Gastric neuroendocrine tumor arising from heterotopic pancreas

There are few English reports on secondary tumors from heterotopic pancreas. Here, we describe a case of gastric neuroendocrine tumor (NET) arising from heterotopic pancreas. A 72-year-old woman underwent esophagogastroduodenoscopy as part of a general health check-up. An endoscopic examination revealed a submucosal tumor on the greater curvature of the gastric body. Laparoscopic and endoscopic cooperative surgery was performed. Histological diagnosis concluded that it was a Grade 1 NET arising from heterotopic pancreas. We report this extremely rare case of a NET presenting as a submucosal tumor, considered to have originated from heterotopic pancreatic tissue.

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.

Perforation of jejunal diverticulum with ectopic pancreas

Perforation of jejunal diverticulum is a rare complication. Here, we report a case of jejunal diverticulum penetration with surrounding ectopic pancreas. An 83-year-old female patient was admitted to our department with acute onset of severe abdominal pain lasting for half a day. Abdominal computed tomography showed outpouching of the small intestine that contained air/fluid, with multiple surrounding air bubbles in the mesentery of the small intestine. She was diagnosed with penetration of the small intestine, and an emergency laparotomy was indicated. The penetrated jejunal diverticulum was identified ~20-cm distal to the ligament of Treitz. Partial resection of the jejunum was performed, and her postoperative course was uneventful. The pathological findings confirmed diverticulum penetration into the mesentery and severe inflammation at the site, with surrounding ectopic pancreas. Furthermore, the pancreatic ducts were opened through the penetrated diverticulum. This rare case shows that the ectopic pancreas might have caused penetration of jejunal diverticulum owing to the pancreatic duct opening through the diverticulum.

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.

Clinical picture: multiple sites of ectopic pancreatic tissue

A case is presented with multiple sites of ectopic pancreatic tissue in the gastro-intestinal tract. The sites were found in the stomach and duodenum, one site of ectopic pancreatic tissue presented with necrotizing pancreatitis. Ectopic pancreatic tissue can be defined as all pancreatic tissue, with no anatomical or vascular continuity with the orthotopic pancreas. The ectopic tissue most likely originates from the spreading of cells, during the allocation of structures derived from the foregut in the embryonic phase. Over ninety percent of ectopic tissue presents in the upper gastrointestinal tract, although other locations have been described. To date this is the first case-report about a patient with multiple localizations of ectopic pancreatic tissue.

Acute ectopic pancreatitis occurring after endoscopic biopsy in a gastric ectopic pancreas

Ectopic pancreas is a congenital anomaly and the most common type of ectopic tissue in the gastrointestinal tract. Most patients with an ectopic pancreas are asymptomatic and rarely have complications. Ectopic pancreatitis after an endoscopic biopsy has not been reported. We report a patient who developed acute ectopic pancreatitis in the stomach after an endoscopic biopsy. A 71-year-old male patient presented with a subepithelial tumor (SET) in the stomach and had no symptoms. Endoscopic ultrasonography demonstrated a 30-mm hypoechoic mural mass, lobulated margins, and anechoic duct-like lesions. To obtain proper tissue specimen, endoscopic biopsy was performed through the opening on the surface of the mass. The pathologic results confirmed an ectopic pancreas. One day after the endoscopic biopsy, he developed persistent epigastric pain. His serum amylase and lipase elevated. Computed tomography of the abdomen showed swelling of the SET and diffuse edema of the gastric wall. His condition was diagnosed as acute ectopic pancreatitis occurring after endoscopic biopsy.

Ectopic pancreas: a diagnostic dilemma

An ectopic pancreas is defined as pancreatic tissue lacking vascular or anatomic communication with the normal body of the pancreas. It is rarely symptomatic as it is found incidentally at laparotomy most of the time. Despite advances in diagnostic modalities, it still remains a challenge to the clinician to differentiate it from a neoplasm. It is prudent to differentiate it from neoplastic etiologies, as simple surgical excision can potentially be curative. We discuss the presentation, diagnosis, and treatment of an interesting case of ectopic pancreas presenting as a gastric antral tumor.

Diffuse Peritonitis due to Perforated Gastric Ectopic Pancreas

Ectopic pancreas is frequently found in the gastrointestinal tract. Lesions comprise well-developed and normally organized pancreatic tissue outside the pancreas, without anatomic or vascular connections with the true pancreas. Most patients with ectopic pancreas are asymptomatic or exhibit nonspecific symptoms. A 68-year-old Japanese woman had been experiencing intermittent pain in the right upper abdomen. Suddenly, the abdominal pain changed to intense pain in the right flank of the abdomen 2 days later. On initial medical examination, the abdomen exhibited rebound tenderness and distension. The results of laboratory tests revealed increased inflammatory reaction. Abdominal computed tomography showed free air and ascites on the surface of the liver and elevated levels of adipose tissue around the antrum and pylorus of the stomach. Perforation of the upper gastrointestinal tract was diagnosed and we performed urgent surgery. The site of perforation, whose size was 25 mm, was the lesser curvature of the antrum of the stomach. Since it was not possible to perform omentopexy, we performed extensive gastric resection. The reconstruction was a Billroth II operation. Microscopic analysis revealed pancreatic tissue within the ulceration, showing islets of Langerhans, acini, and ducts; the lesion was diagnosed as type I using Heinrich's criteria. The postoperative course was uneventful. The patient was discharged on day 13 and remains clinically healthy. Gastric perforation due to ectopic pancreas has been reported in 2 cases, including our patient, and is extremely rare. Once gastric perforation has been diagnosed, the presence of ectopic pancreas might be considered.

The prevalence of pancreatic acinar differentiation in gastric adenocarcinoma: report of a case and immunohistochemical study of 111 additional cases

Although pancreatic acinar metaplasia in the gastric mucosa is well recognized in chronic gastritis, gastric carcinoma with acinar differentiation is very rare. We encountered a case of gastric adenocarcinoma with prominent histologic and immunohistochemical features of pancreatic acinar differentiation in the absence of identifiable heterotopic pancreatic tissue. Distinct glandular and diffuse patterns of adenocarcinoma were also present, and there was focal mucin production. The tumor strongly expressed pancreatic exocrine enzymes trypsin and chymotrypsin, and focal neuroendocrine staining was also present. To investigate the prevalence of acinar differentiation in histologically typical gastric cancers, we performed immunohistochemical staining for trypsin and chymotrypsin on a tissue microarray containing 111 conventional gastric adenocarcinomas (60 intestinal, 28 mixed, 22 diffuse type, and 1 undifferentiated). No obvious morphologic evidence of acinar differentiation was identified in any of the 111 cases. Although some cases showed equivocal staining for at least 1 pancreatic exocrine enzyme on the initial tissue microarray sections, repeat immunohistochemical staining on representative whole-tissue sections failed to reproduce positive staining. Thus, acinar differentiation is rare in gastric adenocarcinomas, other than in histologically unusual cases such as the one we report, and in others from the literature, which are reviewed.

Pancreatic acinar-like adenocarcinoma of the proximal stomach invading the esophagus

The aim of this study was to systematically investigate clinicopathologic features of the recently described pancreatic acinar-like adenocarcinoma of the proximal stomach invading the esophagus (n = 43). Patient median age was 66 years (range, 51-90 years). The male-to-female ratio was 7.6. Grossly, pancreatic acinar-like adenocarcinoma tumors were nonencapsulated with the median size of 5.5 cm (range, 2-10.5). Bormann's types 1 to 4 tumors were in 7%, 9%, 67%, and 16% cases, respectively. Frank necrosis, hemorrhage, and cysts were rare or absent. Lymphovascular (81%), perineural (74%), and lymph node (81%) invasions were more common in the pancreatic acinar-like adenocarcinoma than in the non-pancreatic acinar-like adenocarcinoma (n = 94) groups. Microscopically, pancreatic acinar-like adenocarcinoma tumors showed acinar (78%), micropapillary (12%), microcystic, solid, trabecular, and mixed neuroendocrine or signet ring (33%) patterns of growth. No adenosquamous differentiation was noted in the pancreatic acinar-like adenocarcinoma group. Nuclei were round to oval with thickened nuclear membrane, stippled chromatin, and single prominent nucleoli. Mitotic figures were variable. The cytoplasm was moderate, eosinophilic, finely granular, and diffusely immunoreactive to the α1-chymotrypsin antibody in all cases to various degrees. Tumor stroma was nondesmoplastic, delicate, and fibrovascular. Pancreatic acinar-like adenocarcinoma tumors staged pI, pII, pIII, and pIV were in 2%, 21%, 70%, and 7% of cases, respectively. The median number of follow-up months after surgery was 29. The 2-year survival rate was 67%, lower than that (73%) in the non-pancreatic acinar-like adenocarcinoma group. A worse overall survival trend was found for patients in the pancreatic acinar-like adenocarcinoma than in non-pancreatic acinar-like adenocarcinoma groups, but the difference was not statistically significant. Age older than 75 years and overall pathology stage were independent risk factors.

A clinical and radiologic review of uncommon types and causes of pancreatitis

Acute pancreatitis is one of the most common conditions for which emergent imaging is indicated. Alcohol consumption and cholelithiasis are the most common causes of acute pancreatitis in adults, whereas the majority of cases in children are idiopathic or secondary to trauma. A wide variety of structural and biochemical abnormalities may also cause pancreatitis. Although in some cases it is difficult to identify the specific cause of the disease radiologically, certain uncommon types of acute or chronic pancreatitis may have unique imaging features that can help the radiologist make an accurate diagnosis. These unusual types include autoimmune pancreatitis, groove pancreatitis, tropical pancreatitis, hereditary pancreatitis, and pancreatitis in ectopic or heterotopic pancreatic tissue. Pancreatitis may occasionally be seen in association with cystic fibrosis or pancreas divisum, or secondary to worm infestation of the pancreaticobiliary tree (eg, by Ascaris lumbricoides). In addition, primary pancreatic and duodenal masses may occasionally manifest as acute or recurrent acute pancreatitis. Knowledge of the classic imaging findings of these entities allows prompt recognition of the relevant pathologic condition, thereby preventing misdiagnosis and subsequent inappropriate or delayed management.

Carcinoma developing in ectopic pancreatic tissue in the stomach: a case report

The development of pancreatic tissue outside the confines of the main gland, without anatomic or vascular connections between them, is a congenital abnormality referred to as heterotopic pancreas. A heterotopic pancreas in the gastrointestinal tract is usually discovered incidentally and the risk of its malignant transformation is extremely low. In this study, we describe the first case of endoepithelial carcinoma arising in a gastric heterotopic pancreas of a 56-year old woman in Greece. She presented with epigastric pain, periodic nausea and vomiting. Esophagogastroduodenoscopy revealed an ulcerated lesion in the gastric antrum, biopsies of which showed intense epithelial dysplasia with incipient malignant degeneration. The pathology report of the distal gastrectomy specimen demonstrated a 2 cm in diameter ulcerative mass in the gastric antrum. Microscopically, an endoepithelial (in situ) carcinoma of the gastric antrum was determined, which in places turned into an microinvasive endomucosal adenocarcinoma. It also incidentally demonstrated heterotopic pancreatic ducts, detected within the mucosa to the muscularis propria of the same region of the stomach, in which an endoepithelial (in situ) carcinoma was evolving. The follow-up course was uneventful 6 months postoperatively.

Heterotopic pancreas in the stomach: a case report and literature review

Ectopic pancreas is defined as pancreatic tissue found outside the usual anatomic location of the pancreas. It is often an incidental finding and can be found at different sites in the gastrointestinal tract. It may become clinically evident when complicated by pathologic changes such as inflammation, bleeding, obstruction, and malignant transformation. In this report, a 40 years old woman with epigastric pain due to ectopic pancreatic tissue in the stomach is described. The difficulty of making an accurate diagnosis is highlighted. The patient has remained free of symptoms since she underwent wedge resection of the lesion three years ago. Frozen sections may help in deciding the extent of resection intraoperatively. Although ectopic pancreas is rare, it should be considered in the differential diagnosis of a submucosal gastric tumour.

Heterotopic pancreas in the stomach: a case report and literature review

Ectopic pancreas is defined as pancreatic tissue found outside the usual anatomic location of the pancreas. It is often an incidental finding and can be found at different sites in the gastrointestinal tract. It may become clinically evident when complicated by pathologic changes such as inflammation, bleeding, obstruction, and malignant transformation. In this report, a 40 years old woman with epigastric pain due to ectopic pancreatic tissue in the stomach is described. The difficulty of making an accurate diagnosis is highlighted. The patient has remained free of symptoms since she underwent wedge resection of the lesion three years ago. Frozen sections may help in deciding the extent of resection intraoperatively. Although ectopic pancreas is rare, it should be considered in the differential diagnosis of a submucosal gastric tumour.

Mucinous cyst exhibiting severe dysplasia in gastric heterotopic pancreas associated withe gastrointestinal stromal tumour

Heterotopic pancreatic tissue within the stomach is rare and dysplasia within heterotopic pancreatic tissue is very rare. We present the first report of a patient with concurrent occurrence of heterotopic pancreas in the stomach with a gastrointestinal stromal tumour.

Synchronous occurrence of carcinoid, signet-ring cell carcinoma and heterotopic pancreatic tissue in stomach: A case report and literature review

We presented an unusual case with coexistence of carcinoid, signet-ring cell carcinoma (SRC) and heterotopic pancreatic tissue in stomach. Gastroscopic examination of this 63-year-old male patient showed multiple protrusions in gastric corpus near the greater curvature, identified by subsequent biopsy as carcinoid. Distal subtotal gastrectomy was performed. Histological and immunohistochemical examinations showed a carcinoid tumor in gastric corpus near the greater curvature, an intramucosal SRC at the lesser curvature of corpus and heterotopic pancreatic tissue in muscularis propria of the antrum at the lesser curvature with hyperplasia of peripheral endocrine cells producing multiple pancreatic hormones. We reviewed the literatures on clinicopathological characteristics and the differential diagnosis of the above three abnormalities, and concluded that the carcinoid in corpus near the greater curvature and SRC in the lesser curvature are independent lesions; the foci of endocrine cells in the muscularis propria and serosa are hyperplastic lesions from the heterotopic pancreatic tissue, rather than dissemination of carcinoid in corpus.

Coexistence of carcinoid, signet-ring cell carcinoma and heterotopic pancreas in stomach: a clinicopathological observation

AIM: To report a case with synchronous occurr-ence of carcinoid, signet-ring cell carcinoma (SRC) and heterotopic pancreas in stomach.

METHODS: One male patient aged 63 years old was diagnosed with coexistence of carcinoid, signet-ring cell carcinoma and heterotopic pancreas in stomach by gastroscopy and pathological examination. These three lesions were further observed by histopathological, histochemical and immunohistochemical approaches, with the related literatures reviewed.

RESULTS: Multiple foci of proliferative endocrine cells were found in lamina propria of the corpus, and carcinoid was found in corpus on the greater curve of the stomach, with muscularis mucosae involved. The tumor cells were strongly positive for neuron-specific enolase, synaptophysin and chromogranin A. An intramucosal SRC lesion was found in the lesser curve of corpus. Heterotopic pancreatic tissue was observed in muscularis propria of the antrum on the lesser curve, with hyperplasia of endocrine cells producing multiple pancreatic hormones.

CONCLUSION: Carcinoid in corpus of the greater curve and SRC in the lesser curve are independent lesions; the foci of endocrine cells in the muscularis propria and serosa are hyperplastic lesions from the heterotopic pancreatic tissue, rather than carcinoid dissemination.

Pancreatic heterotopia in the gastric antrum: an ultrastructural report of a case

The author describes a case of pancreatic heterotopia in the gastric antrum detected after histopathological and ultrastructural studies. Bioptic fragments were processed in part for optic microscopy and in part for electron transmission microscopy. Regressive changes were found in the cytoplasm of the exocrine secreting epithelia that led to necrosis of the cells. The changes are consequential and more markedly involve the base area of the secretory epithelia. The changes observed are to be attributed to the absence of excretory activity by the epithelia due to regressive damage of the organelles carrying out this activity.

Adenocarcinoma arising from aberrant pancreas in the stomach

We report herein a rare case of malignant transformation of aberrant pancreas in the stomach, associated with gastric outlet obstruction. A 58-year-old woman was admitted to our hospital, complaining of vomiting. Although barium meal examination and gastric endoscopy showed marked pyloric stenosis, the biopsy specimen obtained from the stenotic site revealed regenerative mucosa without malignancy. Abdominal computed tomography and endoscopic ultrasonography (EUS) also could not detect the cause of the obstruction. Histopathological examination of the surgically resected specimen showed the malignant transformation of aberrant pancreas in the stomach. It should be noted that one of the causes of gastric outlet obstruction may be aberrant pancreas or its malignant transformation.

Gastric neuroendocrine carcinoma arising from heterotopic pancreatic tissue

An 85 year old man presented with symptoms of dyspepsia and increase in stool frequency of two months duration. Upper endoscopy revealed an ulcer and the biopsy was interpreted as carcinoma with endocrine features. A formal distal gastrectomy was planned, but intraoperatively, because of the patient's condition, a wedge resection was performed. Histology revealed a neuroendocrine tumour (grade 1), located mainly in the submucosa, which had caused mucosal attenuation and ulceration. Associated with the tumour and at its periphery was heterotopic pancreatic tissue composed of acini, ducts, and endocrine cells. The tumour was strongly positive for chromogranin and focally for synaptophysin. There was no associated chronic atrophic gastritis or G cell hyperplasia. A discrete focus of high grade neuroendocrine carcinoma (grade 3) within the typical (grade 1) neuroendocrine tumour was also present. This case illustrates a grade 1 neuroendocrine carcinoma, with a small grade 3 focus, arising within or intimately associated with heterotopic pancreatic tissue in the stomach. Although the two entities may be separate, their close topographical association favours the possibility of neuroendocrine carcinoma arising from the heterotopic pancreas. Pathologists should be aware of the occurrence of pancreatic heterotopia in the stomach and the association of carcinoma with it.

Adenocarcinoma arising in gastric heterotopic pancreas: a case report

A heterotopic pancreas in the gastrointestinal tract is mostly found incidentally and its malignant transformation is extremely rare. We describe the second case of adenocarcinoma arising in a gastric heterotopic pancreas of an asymptomatic 35-yr-old man in Korea. Esophagogastroduodenoscopy revealed a submucosal tumor with an irregular central umbilication in the gastric antrum. A wedge resection specimen demonstrated a submucosal oligolocular cystic mass (1.7 x 1.4 x 1.2 cm) with a solid portion. Microscopically, the cystic portion was composed of dilated pancreaticobiliary type ducts with adjacent small foci of periductal glandular structures. The adenocarcinoma components in the solid area infiltrated the proper muscle and the overlying mucosa of the stomach. The transitional area between the benign ductal structures and the adenocarcinoma component was found. The follow-up course was uneventful 5 months postoperatively.

Acinar cell carcinoma arising in the stomach: a case report with literature review

Acinar cell carcinomas (ACCs) are uncommon malignant tumors of the exocrine pancreas, constituting 1% to 2% of all nonendocrine pancreatic neoplasms. Cases of acinar cell carcinoma developing in heterotopic pancreatic tissue are extremely rare. To the best of our knowledge, no cases of primary ACC developing in the stomach have been reported in the literature. We report the first case of a primary ACC arising in the stomach in an 86-year-old female who presented with a 5-cm gastric submucosal mass with superficial ulceration and a history of anemia. The neoplasm exhibited typical acinar morphology. Immunohistochemical studies demonstrated strong positive reactivity for antitrypsin and antichymotrypsin, and electron microscopy confirmed the presence of zymogen granules. A complete metastatic workup failed to identify any primary pancreatic tumor or other nonpancreatic tumor.

Adenocarcinoma arising in association with gastric heterotopic pancreas: A case report and review of the literature

We report a case of adenocarcinoma arising in a focus of heterotopic pancreas, occurring in the stomach of a 52-year-old man. The patient presented with gastric outlet obstruction. Radiographic studies revealed thickening of the gastric wall, but endoscopy failed to reveal a mucosal abnormality. A 50% distal gastrectomy was performed, along with vagotomy. Microscopic examination revealed extensive involvement of the muscularis propria of the distal stomach by heterotopic pancreas. The ectopic pancreas had a microscopic appearance consistent with Heinrich's class III, in which the majority of the heterotopic pancreas was characterized by cystically dilated duct structures. Occasional islets were present. Intimately associated with the cystically dilated ducts was a prominent number of small infiltrating ducts lined by columnar or cuboidal cells with enlarged hyperchromatic nuclei containing prominent nucleoli. These were consistent with a well-differentiated invasive adenocarcinoma. Despite multiple sectioning, no connection between the adenocarcinoma and the overlying gastric mucosa was seen. Adenocarcinoma arising within ectopic pancreas is a rare occurrence with fewer than 30 well-documented cases reported in the world literature to our knowledge.

Development of a simple and sensitive technique for detection of point mutations in the K-ras oncogene

We sought to develop a simple and sensitive method based on mutant allele-specific amplification (MASA) for the detection of point mutations in the k-ras oncogene in blood samples. We used MASA and three nested MASA methods to detect a point mutation (GGT-->GAT) in rat DHD cells at codon 12 of exon 1 of the k-ras gene. MASA allowed us to detect one k-ras mutated cell on a background of 10(7) normal cells. The third nested-MASA (nested-MASA.c) method that we developed allowed us to detect one mutated cell among 10(10) normal cells. Our methods should allow the detection of small amounts of mutant k-ras DNA in tissue, serum, and plasma, combining speed with efficiency and specificity.