Multimodality imaging of pancreatic and biliary congenital anomalies.
Radiographics. 2006
May-Jun;26(3):715-31.
A wide spectrum
of anomalies of the pancreas, the pancreatic ductal system, and the
biliary tree are commonly encountered at radiologic evaluation. These
anomalies may simulate various neoplastic, inflammatory, and
posttraumatic conditions and should be part of the differential
diagnosis for a variety of abnormalities found at diagnostic imaging.
Anatomic variants, developmental anomalies (eg, pancreas divisum,
annular pancreas, ectopic pancreas, pancreatic agenesis and hypoplasia),
and congenital diseases (congenital pancreatic cysts, von
Hippel-Lindau disease, choledochal cysts), in addition to potential
imaging pitfalls (uneven distribution of fat, "pseudomasses"), can all
pose a diagnostic challenge for the radiologist. Familiarity with
these anomalies, the imaging techniques available for their study, and
their variable imaging manifestations is necessary for differentiating
them from other biliary and pancreatic conditions. A basic
understanding of the embryologic development and normal anatomy of the
pancreas and biliary tree is also essential for identifying these
anomalies.
Pancreas. Part I: congenital changes, acute and chronic pancreatitis.
Radiologe.
2006 Apr;46(4):321-35; quiz 336.
The pancreas
develops from ventral and the dorsal buds, which undergo fusion.
Failure to fuse results in pancreas divisum, which is defined by
separate pancreatic ductal systems draining into the duodenum. Risk of
developing pancreatitis is increased in pancreas divisum because of
insufficient drainage. MR cholangiopancreatography (MRCP) is the
technique of choice for detecting pancreas divisum non-invasively.
Annular pancreas is the result of incomplete rotation of the
pancreatic bud around the duodenum with the persistence of parenchyma
or a fibrous band encircling (and sometimes stenosing) the duodenum.
Acute pancreatitis is usually caused by bile duct stones or alcohol
abuse. The Atlanta classification differentiates between mild acute
and severe acute pancreatitis associated with organ failure and/or
local complications such as necrosis, abscess or pseudocyst.
Contrast-enhanced multi-detector row CT is the method of choice to
assess the extent of disease. Balthazar et al.'s CT severity index
assesses the risk of mortality and morbidity. In acute pancreatitis,
the role of MRCP is mainly limited to finding bile duct stones in
patients with suspected biliary pancreatitis. Chronic pancreatitis
results in relentless and irreversible loss of exocrine (and sometimes
endocrine) function of the pancreas. MDCT even shows subtle
calcifications. MRCP is the method of choice for non-invasive
assessment of the duct. Inflammatory pseudotumor in chronic
pancreatitis and groove pancreatitis are difficult to differentiate
from pancreatic cancer. In these cases, multiple imaging methods such
as MDCT, MRI and endosonography including biopsy may be used to make a
diagnosis.
Disorders of the
pediatric pancreas: imaging features.Pediatr
Radiol. 2005 Apr;35(4):358-73.
The purpose of
this manuscript is to provide an overview of the normal development of
the pancreas as well as pancreatic pathology in children. Diagnostic
imaging plays a major role in the evaluation of the pancreas in
infants and children. Familiarity with the range of normal appearance
and the diseases that commonly affect this gland is important for the
accurate and timely diagnosis of pancreatic disorders in the pediatric
population. Normal embryology is discussed, as are the most common
congenital anomalies that occur as a result of aberrant development
during embryology. These include pancreas divisum, annular pancreas,
agenesis of the dorsal pancreatic anlagen and ectopic pancreatic
tissue. Syndromes that can manifest pancreatic pathology include:
Beckwith Wiedemann syndrome, von Hippel-Lindau disease and autosomal
dominant polycystic kidney disease. Children and adults with cystic
fibrosis and Shwachman-Diamond syndrome frequently present with
pancreatic insufficiency. Trauma is the most common cause of
pancreatitis in children. In younger children, unexplained pancreatic
injury must always alert the radiologist to potential child abuse.
Pancreatic pseudocysts are a complication of trauma, but can also be
seen in the setting of acute or chronic pancreatitis from other
causes. Primary pancreatic neoplasms are rare in children and are
divided into exocrine tumors such as pancreatoblastoma and
adenocarcinoma and into endocrine or islet cell tumors. Islet cell
tumors are classified as functioning (insulinoma, gastrinoma, VIPoma
and glucagonoma) and nonfunctioning tumors. Solid-cystic papillary
tumor is probably the most common pancreatic tumor in Asian children.
Although quite rare, secondary tumors of the pancreas can be
associated with certain primary malignancies.
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