Ampullary Carcinoma
It represents around a 4% of periampullary tumours.
It grows from the glandular epithelium of the ampulla and it is currently considered as a duodenal cancer.
It is more frequent in the male sex,
60-70 y.o.
Usually,
the tumour is small at the moment of the diagnosis because of the early obstructive symptoms (Fig 3).
Pancreatic carcinoma
80% of cases are localized in the head.
Ductal adenocarcinoma is the most frequent histologic group (85%).
Despite small size at the moment of the diagnosis,
most of pancreatic adenocarcinomas are irresectable because of local extension or the presence of metastasis (Fig 4).
Islet cell tumours of the pancreas are neuroendocrine tumours that produce and secrete hormones at a variable range.
They rarely produce pancreatic ductal dilatation.
They are typically hypervasculated so they generally are better seen at arterial phase CT (Fig 5 and Fig 6).
We can find insulinomas,
gastrinomas,
glucagonomas,
VIPomas and somatostatinomas in decreasing order of frequency
.
Traditionally,
the term pancreatic carcinoid meant pancreatic island cell tumour or pancreatic neuroendocrine tumour,
but at the present time,
pancreatic carcinoid is defined as the pancreatic endocrine tumour that expresses serotonin (Fig 7,
Fig 8,
Fig 9 y Fig 10).
Cystic tumours of the pancreas must be differentiated from cystic components of adenocarcinomas,
from tumours of the islands of the pancreas,
and from pseudocysts,
because of the different management.
On the basis of different morphologic features,
the presence of a solid component and its origin (serous or mucinous),let us make a useful classification to guide the management,
prognosis and follow-up (Fig 11).
Cholangiocarcinoma
Cholangiocarcinoma is the second primary hepatic tumour in order of frequency after hepatocellular carcinoma.
It arises in the bile duct epithelium and it is classified in intrahepatic and extrahepatic.
Extrahepatic has an infiltrative or a polipoid grow.
They produce a proximal bile duct dilatation and,
in case of main pancreatic duct dilatation,
it is because of the infiltration of the gland.
Periampullary duodenal carcinoma
It is an infrequent neoplasm that typically produces local invasion.
It can produce biliary dilatation or pancreatic duct dilatation in a variable way.
66% of these tumours are exophytic and polipoids and,
in the rest of the cases,
the tumour is ulcerative.
Pancreatitis
Acute pancreatitis varies from a mild episode and practically asymptomatic to a severe disease with risk of multiorganic failure.
Alcohol abuse and the presence of lithiasis are the most common causes that predispose to acute pancreatitis.
The presence of typical symptoms and personal history are essential to distinguish between pancreatitis and a tumoural process (Fig 12).
In chronic pancreatitis,
alcoholism is the most common cause,
although there are other causes such as neoplasms,
stenosis and very low protein diets (Fig 13 and Fig 14).
Pseudocysts
They are well defined fluid collection that is rich in amylase and other pancreatic enzymes,
that have a nonepithelialised wall consisting of fibrous and granulation tissue. It can be uniloculated or multiloculated,
rounded or oval,
with a thick wall or a thin wall.
This entity appears in patients with history of acute or chronic pancreatitis.
They are associated to peripancreatic inflammatory changes,
atrophia or calcification of the pancreatic parenchyma,
dilatation and pancreatic duct stones (Fig 15).
Papilitis
It is an acute inflammatory disorder involving the mucosa overlying the major duodenal papilla.
It may reflect an underlying biliary or pancreatic disorder.
It can be seen in the context of a cholangitis,
acute pancreatitis,
biliar lithiasis or a sphincterotomy.
Bulging of the papilla with increased enhancement may be clues to the detection of an isoattenuating bile duct stone or recently passed stone.
Symmetric wall thickening and increased contrast enhancement may help distinguish benign papillitis from hypovascular malignant conditions.
(Fig 16 and Fig 17).
Adenopathies
Sometimes,
physiologic structures such as lymphatic glands or pathologic lymphadenopathies sited in periampullary region can be mistaken with neoplasms (Fig 18).
Biliary stones
Choledocolithiasis is the most frequent cause of biliar duct obstruction.
Approximately 5-10% of patients with cholelithiasis also have choledocolithiasis (Fig 19 and Fig 20).