[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Pancreas](https://durgical.com/en/general-pathology/areas/pancreas/) › Congenital anomalies of the pancreas

# Congenital anomalies of the pancreas

- Lesion

The pancreas forms from two buds that must fuse; when they do not fuse or rotate well, ducts drain badly or the gut is squeezed.

Updated Nov 12, 2026

## Key points

- Pancreas divisum: most of the gland drains through the small minor papilla (duct of Santorini); most people are asymptomatic, a minority develop pancreatitis.
- Annular pancreas: ring around the second part of the duodenum; can cause duodenal obstruction; associated with Down syndrome and duodenal atresia.
- Ectopic pancreas: commonest in stomach and duodenum; may cause pain, bleeding or a submucosal nodule mistaken for a tumour.
- Ectopic pancreas can itself develop pancreatitis or, rarely, neoplasms.
- Agenesis of the whole pancreas is very rare and usually not compatible with long survival without treatment.

## What it is

The pancreas develops from dorsal and ventral foregut buds that fuse between the fifth and eighth weeks. Pancreas divisum (failed fusion of the duct systems) is the most common variant; annular pancreas (a ring of pancreas around the duodenum) comes from abnormal rotation of the ventral bud. Ectopic pancreatic tissue is found in the stomach, duodenum, jejunum or a Meckel diverticulum. Agenesis is very rare and linked to mutations such as PDX1.

## Structure

- Ectopic pancreas: a submucosal yellow nodule with acini, ducts and sometimes islets; often a central umbilication.

## Step by step

- The dorsal bud forms most of the head, body and tail and drains through the duct of Santorini.
- The ventral bud rotates with the bile duct behind the duodenum and forms the rest of the head.
- Normally the buds and their ducts fuse; the main duct of Wirsung drains at the major papilla.
- If ducts fail to fuse, the dorsal pancreas drains through the minor papilla: divisum.
- If the ventral bud splits or rotates abnormally, a ring encircles the duodenum: annular pancreas.

## Congenital anomalies of the pancreas

| Anomaly | Embryologic error | Clinical relevance |
| --- | --- | --- |
| Pancreas divisum | Dorsal and ventral ducts fail to fuse | Relative outflow obstruction at the minor papilla; recurrent pancreatitis in a minority |
| Annular pancreas | Abnormal rotation of the ventral bud | Band around the duodenum; duodenal obstruction, vomiting in newborns |
| Ectopic pancreas | Pancreatic rests in the gut wall | Submucosal nodule; pain, bleeding, rarely pancreatitis or tumour |
| Agenesis | Failure of bud formation (e.g. PDX1 mutation) | Neonatal diabetes and exocrine insufficiency |

## Memory aid

Two buds, one gland: if their pipes don't join you get divisum; if one bud wraps the duodenum you get a ring.

## Test yourself

Think of the answer, then tap the question to see it.

## What is the most common congenital anomaly of the pancreas?

Pancreas divisum, failure of fusion of the dorsal and ventral duct systems.

## Which congenital pancreatic anomaly can obstruct the duodenum?

Annular pancreas, a ring of pancreatic tissue around the second part of the duodenum.

## Where is ectopic pancreatic tissue most often found?

In the stomach and duodenum, followed by the jejunum, Meckel diverticulum and ileum.

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## Elsewhere in DurgiPedia

- [Annular pancreas and pancreas divisum](https://durgical.com/en/embryology/annular-pancreas-and-pancreas-divisum/)
- [Liver, gallbladder and pancreas](https://durgical.com/en/embryology/liver-gallbladder-and-pancreas/)
- [Pancreas: acini and islets](https://durgical.com/en/histology/pancreas-acini-and-islets/)

## Connections

## Related 3

- [Acute pancreatitis: causes, and how trypsin starts self-digestion](https://durgical.com/en/general-pathology/acute-pancreatitis-causes-and-how-trypsin-starts-self-digestion/)
- [Chronic pancreatitis: fibrosis, ductal stones and lost acini](https://durgical.com/en/general-pathology/chronic-pancreatitis-fibrosis-ductal-stones-and-lost-acini/)
- [Non-neoplastic pancreatic cysts: congenital cysts and pseudocysts](https://durgical.com/en/general-pathology/non-neoplastic-pancreatic-cysts-congenital-cysts-and-pseudocysts/)

## Related conditions 5

- [Chronic pancreatitis](https://durgical.com/en/conditions/chronic-pancreatitis/)
- [Acute pancreatitis](https://durgical.com/en/conditions/acute-pancreatitis/)
- [Meckel diverticulum](https://durgical.com/en/conditions/meckel-diverticulum/)
- [Duodenal and intestinal atresia](https://durgical.com/en/conditions/duodenal-and-intestinal-atresia/)
- [Down syndrome (trisomy 21)](https://durgical.com/en/conditions/down-syndrome/)

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Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.

Sources: [Pancreas divisum: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/000247.htm) (MedlinePlus, US National Library of Medicine, 2026); [Annular pancreas: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/001142.htm) (MedlinePlus, US National Library of Medicine, 2026).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/general-pathology/congenital-anomalies-of-the-pancreas/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/congenital-anomalies-of-the-pancreas/