# Somatostatinoma

Source: https://onco.cc/cancers/somatostatinoma/  
OnCo record `somatostatinoma` (Cancer). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Somatostatinoma is one of the rarest neuroendocrine tumours, arising in the pancreas or the duodenum and secreting somatostatin, a hormone that switches off digestion, which can cause mild diabetes, gallstones and fatty diarrhoea. Duodenal cases are often linked to neurofibromatosis type 1 and rarely cause symptoms. Surgery is the main treatment and the outlook depends on site and grade.

## Summary

Somatostatinoma is a rare neuroendocrine tumour of delta cells, about 1 percent of gastroenteropancreatic endocrine neoplasms, most often in the duodenum followed by the pancreas; it may be sporadic or associated with neurofibromatosis type 1, MEN1 and von Hippel-Lindau disease, and functional tumours cause the inhibitory syndrome of mild diabetes, cholelithiasis and diarrhoea or steatorrhoea by suppressing gallbladder motility and endocrine and exocrine secretion, while non-functional tumours are asymptomatic or obstructive (J Gastroenterol Hepatol 2008). The incidence is about 1 in 40 million; duodenal and periampullary tumours cause jaundice or pancreatitis, and the NF1 association reflects RAS-MAPK pathway dysfunction, with the Pacak-Zhuang syndrome (EPAS1) a rarer genetic setting; surgery is central where feasible and prognosis depends on location and WHO grade (Experimental and Therapeutic Medicine 2020).

How it differs from its parent: it is the functioning tumour whose hormone inhibits rather than stimulates, so its syndrome is subtle and most cases are found by obstruction or incidentally; duodenal tumours are usually small, often psammomatous and syndromic, whereas pancreatic tumours are larger and more often metastatic.

How common: about 1 in 40 million (Experimental and Therapeutic Medicine 2020).

Treatment: resection (pancreatoduodenectomy or local excision by size and site); the parent page's pathways (somatostatin analogues, everolimus, sunitinib, peptide receptor radionuclide therapy) for metastatic disease, with grade guiding the choice; NF1 patients are screened for other tumours.

## Fields

- Kind: Cancer
- Last checked: 2026-09-24
- Also known as: Somatostatin-secreting neuroendocrine tumour; Duodenal somatostatinoma; Delta-cell tumour; Inhibitory syndrome tumour
- Tags: subtype-page; wave4; rare
- Group: endocrine
- Burden: About 1 percent of gastroenteropancreatic endocrine neoplasms, with roughly 200 published cases by 2008 (J Gastroenterol Hepatol 2008); an incidence of about 1 in 40 million people (Experimental and Therapeutic Medicine 2020).
- Subtypes: Duodenal somatostatinoma (often NF1-associated, psammomatous, small); Pancreatic somatostatinoma (larger, more often metastatic); Functional somatostatinoma with the inhibitory syndrome; Non-functional somatostatin-expressing neuroendocrine tumour (incidental or obstructive)
- Biomarkers: Plasma somatostatin; NF1 status; MEN1 and VHL in syndromic cases; WHO grade (Ki-67) and site; Somatostatin receptor imaging

## Sections of this record

The page is a hub with ten sections in reading order; large sections have their own page. The same plan as JSON: https://onco.cc/api/v1/cancers/somatostatinoma/sections.json

- Overview (on the hub): The TL;DR, the family this cancer belongs to, the organ, who gets it and what the state of the art is. https://onco.cc/cancers/somatostatinoma/#overview
- What it is (on the hub): Anatomy, the subtypes and how they differ, how it is staged, and where advanced disease spreads. https://onco.cc/cancers/somatostatinoma/#what-it-is [4 subtypes]
- Finding it (on the hub): How it shows itself, how it is confirmed, what screening exists, and the biomarkers clinicians test for. https://onco.cc/cancers/somatostatinoma/#finding-it [4 biomarkers]
- Treating it (on the hub): The standard of care by setting, the medicines, surgery and radiotherapy named in it, and the regimens behind them. https://onco.cc/cancers/somatostatinoma/#treating-it [1 setting, 1 decision with options]
- Evidence (on the hub): Trials recruiting now, the landmark trials, the key papers and what they mean, the latest literature, and the milestones year by year. https://onco.cc/cancers/somatostatinoma/#evidence
- The science (on the hub): The molecular landscape: the targets and how often each appears, the pathways, the mechanics stages and the preclinical models. https://onco.cc/cancers/somatostatinoma/#science [5 targets]
- Where you are (own page): Cases by country, the UK and NHS pathway and other country lenses, and the expert centres with trials on record. https://onco.cc/cancers/somatostatinoma/where-you-are/
- Living with it (on the hub): The decisions you may face, the aids that walk through them, the warnings on record, the first sixty days and the questions to ask. https://onco.cc/cancers/somatostatinoma/#living-with-it [8 questions, 6 red cards]
- What is coming (own page): Everything in development, the open problems and what is being done about them, the roadmaps, and what changed on this record. https://onco.cc/cancers/somatostatinoma/coming/ [2 medicines]
- Data (own page): Every connected record, the notes, the JSON, Markdown and RDF twins, and where the record came from and when it was checked. https://onco.cc/cancers/somatostatinoma/data/ [13 connected records]

## Standard of care

- All cases: Resection by size and site; the parent page's pathways for metastatic disease; screening of NF1 patients for other tumours. ([Pancreatic neuroendocrine tumours](https://onco.cc/cancers/pancreatic-net/), [Everolimus](https://onco.cc/drugs/everolimus/), [Sunitinib](https://onco.cc/drugs/sunitinib/), [Peptide receptor radionuclide therapy (PRRT)](https://onco.cc/technologies/prrt/))

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Somatostatinoma
- NCI PDQ: pancreatic neuroendocrine (islet cell) tumour treatment: https://www.cancer.gov/types/pancreatic/neuroendocrine-tumors/treatment
- J Gastroenterol Hepatol 2008: somatostatinoma, three cases and literature review: https://doi.org/10.1111/j.1440-1746.2007.05053.x
- Experimental and Therapeutic Medicine 2020: somatostatinoma beyond neurofibromatosis type 1 (review): https://doi.org/10.3892/etm.2020.8965

## Connected records

- cancers: [Glucagonoma](https://onco.cc/cancers/glucagonoma/), [Multiple endocrine neoplasia type 1 (MEN1)](https://onco.cc/cancers/men1-syndrome/), [Pancreatic neuroendocrine tumours](https://onco.cc/cancers/pancreatic-net/), [Small intestinal neuroendocrine tumours](https://onco.cc/cancers/small-intestinal-net/), [VIPoma](https://onco.cc/cancers/vipoma/)
- technologies: [Peptide receptor radionuclide therapy (PRRT)](https://onco.cc/technologies/prrt/)
- targets: [NF1 (neurofibromin)](https://onco.cc/targets/nf1/)
- drugs: [Everolimus](https://onco.cc/drugs/everolimus/), [Sunitinib](https://onco.cc/drugs/sunitinib/)

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JSON: https://onco.cc/api/v1/entities/somatostatinoma.json