Objectives

- To review the pancreas embryology including the two ventral buds-theory

- To know the clinical implication of congenital variants and anomalies of the pancreas

- To review diagnostic imaging of most common variants and anomalies

- To discuss imaging technics allowing more precise ductal configuration study

- To review the subtypes and classifications attempts of annular and circumportal pancreas

Background

As some developmental anomalies of the pancreas can lead to diseases and anatomical variants mimic lesions or result in surgical risks, radiologists should be familiar with the main pancreatic variants.

Imaging findings OR Procedure findings

- Usual anatomy and embryologic development

- Anomalies and variations (of development, rotation and fusion) of the pancreatic buds :

> Total or partial agenesis

> Ectopic pancreas

> Annular pancreas

> Circumportal pancreas

- Anomalies and variations of the pancreatic ducts :

> Pancreatobiliary junction

> Downstream ductal configuration

> Pancreas divisum

> Pancreas bifidum

- Anomalies of parenchymal development and cell differentiation :

> Focal or sectorial: focal fatty infiltration versus lipomas, focal fatty sparing, contour variation (prominent focal exophytic lobulation between peritoneal reflections)

> Diffuse: genetic (Shwachman-Diamond, Johanson-Blizzard) versus acquired lipomatous infiltration

- Anomaly of the splenic anlage: intrapancreatic accessory spleen

Conclusion

Pancreatic variants and developmental anomalies can be diagnosed accurately using CT and/or MR imaging. The understanding of their embryological origins may help radiologists in their diagnosis.