The pancreatic ductal embryology is moderately complicated, leading to a number of anatomical variants of its ducts, many of which are clinically significant.
There are two main end ducts within the pancreas
Duct of Wirsung
- embryologically is the dorsal bud duct (which goes on to part of the head and uncinate process of the pancreas).
- drains at the ampulla of Vater.
- connects with the duct of Santorini to form the main pancreatic duct (contributes the head portion).
Duct of Santorini
- embryologically is the ventral bud duct (which goes on to part of the head, body and tail of the pancreas).
- drains at the minor papilla if present.
- connects with the duct of Wirsung to form the main pancreatic duct (contributes the body and tail portion).
A pancreas divisum is the most common variation of pancreatic duct formation and can account for up to 14 % 3. It results from failure of fusion of dorsal and ventral pancreatic anlages. As a result, the dorsal pancreatic duct drains most of the pancreatic glandular parenchyma via the minor papilla. Although controversial, this variant is considered as a cause of pancreatitis1,3.
Pancreatic divisum can result in a santorinicele 2, which is a cystic dilatation of the distal dorsal duct, immediately proximal to the minor papilla .
Three sub types are known
- type 1 : classic : no connection at all : occurs in the majority of cases : ~ 70% 5
- type 2 : absent ventral duct : minor papilla drain all of pancreas while major papilla drains bile duct : ~ 20 - 25 % 5
- type 3 : functional : filamentous or inadequate connection between dorsal and ventral ducts : ~ 5 - 6 % 5
An annular pancreas is an uncommon ( ≈ 1 in 20000 1) variation with partial or complete surrounding of the duodenum with pancreatic tissue. The ventral pancreatic "anlage" is responsible for this anomaly by dividing early into 2 segments.
- often detected incidentally in asymptomatic patients
- may be associated with duodenal stenosis, postbulbar ulcerations, pancreatitis or biliary obstruction
Rare branching anomaly of the pancreas tail and its duct system, also known as fishtail pancreas6.
Ectopic pancreatic tissue
Ectopic pancreatic tissue refers to pancreatic rests that lie outside and separate to the pancreatic gland. It is reportedly quite common, affecting 1 - 10% 1 of people, most of whom are completely asymptomatic.
- 1. Yu J, Turner MA, Fulcher AS et-al. Congenital anomalies and normal variants of the pancreaticobiliary tract and the pancreas in adults: part 2, Pancreatic duct and pancreas. AJR Am J Roentgenol. 2006;187 (6): 1544-53. doi:10.2214/AJR.05.0774 - Pubmed citation
- 2. Manfredi R, Costamagna G, Brizi MG et-al. Pancreas divisum and "santorinicele": diagnosis with dynamic MR cholangiopancreatography with secretin stimulation. Radiology. 2000;217 (2): 403-8. Radiology (full text) - Pubmed citation
- 3. Soto JA, Lucey BC, Stuhlfaut JW. Pancreas divisum: depiction with multi-detector row CT. Radiology. 2005;235 (2): 503-8. doi:10.1148/radiol.2352040342 - Pubmed citation
- 4. Shanbhogue AK, Fasih N, Surabhi VR et-al. A clinical and radiologic review of uncommon types and causes of pancreatitis. Radiographics. 29 (4): 1003-26. doi:10.1148/rg.294085748 - Pubmed citation
- 5. Warshaw AL, Simeone JF, Schapiro RH et-al. Evaluation and treatment of the dominant dorsal duct syndrome (pancreas divisum redefined). Am. J. Surg. 1990;159 (1): 59-64. - Pubmed citation
- 6. Dinter D, Löhr JM, Neff KW. Bifid tail of the pancreas: benign bifurcation anomaly. AJR Am J Roentgenol. 2007;189 (5): W251-3. doi:10.2214/AJR.05.1453 - Pubmed citation
Synonyms & Alternative Spellings
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