Gastric neuroendocrine carcinoma arising from heterotopic pancreatic tissue

Abstract

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.

A Case of Dual Intussusception

“…Heterotopic pancreas has been classified into four types. Type I with total pancreatic heterotopia with all pancreatic cell types present, Type II is composed of pancreatic ducts only (the so called canalicular variety), Type III comprise acinar tissue only (exocrine pancreas), and Type IV is of islet cells only (endocrine pancreas) [2]. The histological classification of the heterotopic pancreas in our case was Type III.…”

“…Pancreatic heterotopia can develop due to either metaplasia of multipotent endodermal cells in situ or transplantation of embryonic pancreatic cells to adjacent structures. The common gastrointestinal sites of occurrence include the stomach, duodenum, jejunum, Meckel's diverticulum, gallbladder and oesophagus [2]. Heterotopic pancreas as a lead point of intussusception has been reported [6] with one study describing it as a new variant in the development of vitellointestinal tract malformation [7].…”

“…Multiple sections of the inverted diverticulum showed all layers of the intestine. Histological examination of the fleshy nodule showed pancreatic tissue with acini and ducts with irregular bundles of smooth muscle tissue (Type III heterotopia) [2]. There was no stromal reaction, necrosis, mitosis or dysplasia (Fig.…”

Therapeutic Management of Submucosal Gastric Tumors: A Series of Six Cases with Ectopic Pancreas in the Stomach and Description of a Novel Endoscopic Full-Thickness Resection Technique of the Gastric Wall

“…Type II shows pancreatic tissue with ducts and acini but no islet cells, and Type III characterizes pancreatic tissue with large numbers of ducts and few acini (Figures 6a-6c) [18]. Malignancies of ectopic pancreas have been reported in the literature, though the incidence is very rare [8,19].…”

Variants of Gastric Carcinoma: Morphologic and Theranostic Importance

“…Because pancreatic heterotopia is relatively common in the stomach, origin in heterotopic pancreatic tissue was proposed first. Some ACCSs arising from heterotopic pancreas have been reported [158][159][160][161][162][163]. Acinar cell metaplasia is a relatively common finding in the gastric mucosa, either as a congenital abnormality, or in association with chronic gastritis [164][165][166][167].…”