Small-cell neuroendocrine carcinoma of the ileum: case report and literature review

Molecular Classification of Gastrointestinal and Pancreatic Neuroendocrine Neoplasms: Are We Ready for That?

In the last two decades, the increasing availability of technologies for molecular analyses has allowed an insight in the genomic alterations of neuroendocrine neoplasms (NEN) of the gastrointestinal tract and pancreas. This knowledge has confirmed, supported, and informed the pathological classification of NEN, clarifying the differences between neuroendocrine carcinomas (NEC) and neuroendocrine tumors (NET) and helping to define the G3 NET category. At the same time, the identification genomic alterations, in terms of gene mutation, structural abnormalities, and epigenetic changes differentially involved in the pathogenesis of NEC and NET has identified potential molecular targets for precision therapy. This review critically recapitulates the available molecular features of digestive NEC and NET, highlighting their correlates with pathological aspects and clinical characteristics of these neoplasms and revising their role as predictive biomarkers for targeted therapy. In this context, the feasibility and applicability of a molecular classification of gastrointestinal and pancreatic NEN will be explored.

Multiple Small Intestinal Neuroendocrine Tumors With Findings of Intestinal Obstruction

Carcinoid tumors are one of the most common types of small intestinal neuroendocrine tumors (SI-NETs). However, SI-NETs that manifest as subacute intestinal obstruction are extremely rare. The annual occurrence rate of jejuno-ileal NETs is 0.28-0.8 per 100,000 people. In this report, we describe a case of subacute intestinal obstruction due to a mid-ileal stricture. The patient underwent laparotomy after evaluation and investigation. Mid-ileal growth was noted, and small bowel resection was performed with primary end-to-end anastomosis. Postoperative histopathology revealed the growth to be a well-differentiated NET.

Neuroendocrine neoplasms of the duodenum, ampullary region, jejunum and ileum

Neuroendocrine neoplasms of the small intestine are some of the most frequently occurring along the gastrointestinal tract, even though their incidence is extremely variable according to specific sites. Jejunal-ileal neuroendocrine neoplasms account for about 27% of gastrointestinal NETs making them the second most frequent NET type. The aim of this review is to classify all tumors following the WHO 2019 classification and to describe their pathologic differences and peculiarities.