Gastric neuroendocrine tumor arising from heterotopic pancreas

Diagnosis of Ectopic Pancreas in Small Intestine With 18F-DOPA PET/CT

ABSTRACT

A 77-year-old man was referred for a PET/CT 18F-FDG after incidental discovery of a lobulated jejunal lesion during surgery for an abdominal aortic aneurysm. The lesion was not removed due to the risk of digestive perforation. PET/CT 18F-FDG did not show pathologic hypermetabolism. Subsequently, we decided to perform PET/CT 18F-DOPA to better characterize this incidentaloma. A moderate uptake was showed, less than the pancreas. After multidisciplinary discussion, taking into account macroscopic and imaging aspects, the hypothesis of an ectopic pancreas was retained, allowing the exclusion of surgical excision.

A Case of Myoepithelial Hamartoma: Morphological Variation Supported by OCT4 Expression

In this report, we describe a patient with myoepithelial hamartoma, which is regarded as synonymous with adenomyosis and heterotopic pancreas. Endoscopy revealed a submucosal tumor in the antrum of the stomach. Subsequently, distal gastrectomy with Roux-en-Y reconstruction was performed. Histological findings of adenomyomatous lesion and heterotopic pancreatic tissue were observed in this lesion. The distribution of OCT4, which is a pluripotency marker, varied in each part.

Cutting the edge between cancerogenesis and organogenesis of the pancreatic endocrine lineage allocation-comprehensive review of the genes Synaptotagmin 13 and 533041C22 Rik in epithelial-to-mesenchymal transition

In the past years, a multitude of studies has been published in the field of pancreatic organogenesis to interrogate the critical regulators of endocrine lineage segregation. Preliminary, transcription factors are guiding the transcriptional hierarchy of the endocrine specified cells, underpinning the importance of open chromatin formation. Signaling pathways either inhibit or accelerate the transcriptional landscape of pancreatic organogenesis. Thus, the fine-tuned process in the former pancreatic multipotent progenitors in the mechanism of lineage segregation needs to be elucidated more precisely for unraveling the temporal-spatial lineage-determining factors.

Previously, Willmann et al. described candidate gene regulators of lineage segregation during the secondary transition of pancreatic organogenesis. At embryonic stage (E) 12.5, the former multipotent pancreatic progenitor compartmentalizes into the acinar, ductal, and endocrine lineage. In the adult pancreatic gland, acinar cells secrete enzymes that are transported by the duct to the duodenum. In contrast, the endocrine cells are clustered within the acinar tissue in the Islets of Langerhans. These Islets of Langerhans consist of a subset of α, δ, ε, and PP cells and β cells, and the function of the α and β cells is predominantly described by regulating glucose homeostasis, contrary, the function of the additional subtypes in the Islets of Langerhans remains still unclear and is rather pointing to a supportive role for the α and β cells.

The essential wave of endocrine precursor cells emerges at E 14.5 out of the ductal cord-like structure in a process called epithelial-to-mesenchymal transition (EMT). This EMT is a reversible and incomplete process that includes significant intermedia states. As EMT is in focus in the field of cancer research, missense in endocrine lineage segregation is linking to a progression of pancreatic cancer, to be more precise in adenocarcinoma, e.g., meaning pancreatic ductal adenocarcinoma.

Thus, the previous review will further accelerate the understanding of EMT about endocrine lineage segregation, respective pancreatic ductal adenocarcinoma, and introduces factors previously only known for either lineage segregation or related in cancer disease into a complete picture.

A Rare Case of Well-Differentiated Neuroendocrine Tumor Arising From a Jejunal Pancreatic Heterotopia

Pancreatic heterotopia is a well-described entity occurring at multiple abdominal sites, most commonly the stomach and small intestine. They can develop similar disease processes as the pancreas ranging from acute pancreatitis, cyst formation, or neoplasms, most commonly ductal adenocarcinoma. Neuroendocrine tumors (NETs) arising in pancreatic heterotopias are exceedingly rare with only 3 prior published cases. In this article, we describe the first reported case of a NET arising in a jejunal pancreatic heterotopia in a 59-year-old woman presenting with abdominal pain and diarrhea. The submucosal tumor was composed of a well-differentiated NET (World Health Organization grade 1) directly intermixed with a heterotopic pancreas consisting of acinar cells, islet cells, and ducts. This case illustrates that NETs can occur in association with pancreatic heterotopias at any site. Also, the importance for pathologists to recognize that pancreatic heterotopias can give rise to a variety of neoplasms and is not limited to ductal adenocarcinoma.

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.

Ectopic Pancreas in the Gastric Antrum Wall Complicated by Ectopic Pancreatitis and Persistent Gastric Abscess

Ectopic pancreas is an uncommon finding in the stomach. Complications are rare but can lead to significant morbidity and even mortality. We report a 49-year-old man who presented with upper abdominal pain, vomiting, and weight loss and was found to have a gastric wall abscess that developed a few weeks after endoscopic biopsy of a gastric ulcer. After medical treatment failed to resolve his symptoms, he underwent distal gastrectomy with Roux-en-Y gastrojejunostomy. Postoperatively, the gastric wall abscess was determined to have derived from a focus of ectopic pancreatic tissue with evidence of ectopic chronic pancreatitis.