Mistakes in ... 2021 - 13

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Mistakes in... 2021
Mistakes in endoscopic ultrasonography and how to avoid them
Andrada Seicean and Rodica Gincul
Examination of the pancreas and biliary and digestive structures by endoscopic
ultrasonography (EUS) can be tricky and using it to make a diagnosis can be challenging.
Understanding anatomical variations and postoperative modifications is vital when
undertaking EUS, as is choosing the correct linear echoendoscope for the structures being
examined (e.g. the hilum of the liver versus the tail of the pancreas). There can also be
difficulties with tissue acquisition related to tumour location and internal structures, and there
are situations when sampling is contraindicated. Consideration also needs to be given to the
use of contrast with special settings and difficulties in differential diagnosis (pancreatic solid
lesions, indeterminate biliary strictures, gastric neuroendocrine tumours). The role of EUS
assessment after neoadjuvant therapy should also be considered. Here we discuss the most
frequent mistakes that are made in pancreatobiliary and digestive EUS imaging.
Mistake 1 Failing to understand the
anatomical structure of the
pancreatobiliary region
Pancreatic echogenicity on ultrasound is normally
equal to or slightly greater than that of the liver.1
However, sometimes the lobular architecture of
the pancreas is so pronounced it is suspicious
for chronic pancreatitis (figure 1). Increased
echogenicity in the pancreatic parenchyma is
not uncommon and can be mistaken for chronic
pancreatitis during EUS examination. Hyperechoic
pancreatic changes are frequently encountered in
elderly and obese patients,2,3
and understanding
the possible variations in pancreatic echostructure
and echogenicity is fundamental for accurate EUS
diagnosis. The lack of pancreatic parenchyma
calcifications and especially the presence of a
normal pancreatic duct can help exclude chronic
pancreatitis.4
On EUS, the ventral anlage of the uncinate
process is often hypoechoic in appearance and
may be suggestive of a hypoechoic focal lesion
(figure 2a).5
However, the absence of clear
margins and a nondilated common bile
duct (CBD) and pancreatic duct may help
differentiate the ventral anlage from a pancreatic
tumour. In case of diagnostic doubt, contrastenhanced
harmonic EUS imaging (CH-EUS)-a
new sonographic technique that depicts
intratumoural vessels in real time-can be
helpful. CH-EUS improves the characterization
of pancreatic lesions and discriminates between
malignant and benign ones. In several studies,
the hyposignal (hypoenhancement compared
with the surrounding parenchyma) was a highly
accurate sign of malignancy.6
In the absence of a
focal lesion, the entire parenchyma is enhanced
homogeneously (figure 2b).
EUS is the most sensitive imaging procedure
for the detection and characterization of
pancreatic tumors;7
however, the diagnostic
performance for detection of pancreatic
malignancy can be altered when associated with
the following factors: chronic pancreatitis, a
diffusely infiltrating carcinoma, a prominent
ventral/dorsal split and a recent (<4 weeks)
episode of acute pancreatitis.8,9
CH-EUS may
be useful for diagnosing pancreatic carcinoma
in these situations, because its high negative
predictive value (NPV) is greater than that of
EUS-FNA (fine needle aspiration).10
If there a high
clinical suspicion of pancreatic cancer and EUS
examination is negative, a repeat EUS after
2-3 months may be necessary to detect the
missed neoplasm.8
EUS is of great value for the diagnosis of
Figure 1 | Pronounced lobular architecture of the pancreas may seem suspicious for chronic pancreatitis with
a normal main pancreatic duct.
© 2021 Seicean and Gincul.
Cite this article as: Seicean A and Gincul R. Mistakes in endoscopic
ultrasonography and how to avoid them. UEG Education 2021; 21: 1-9.
Andrada Seicean is Professor of Gastroenterology and Internal
Medicine at the University of Medicine and Pharmacy Iuliu
Hatieganu Cluj-Napoca, Romania, working in the Regional
Institute of Gastroenterology and Hepatology Cluj-Napoca,
Romania. Rodica Gincul works working in the Department of
Gastroenterology and Endoscopy, Jean Mermoz Private Hospital,
Lyon, France.
bile duct lithiasis, but it can be challenging in
the presence of a periampullary diverticulum,
particularly if it is large and obstructed with
debris. Intradiverticular papilla can also confuse
matters because of air artifacts that can produce
a false stone-like image leading to unnecessary
endoscopic retrograde cholangiopancreatography
(ERCP). Filling the duodenum with water so that
the papilla is submerged and free of air bubbles
can avoid this issue.
Images: A. Seicean and R. Gincul
Correspondence to: andradaseicean@gmail.com
Conflicts of interest: The authors declare they have no conflicts of
interest in relation to this article.
Published online: January 29, 2021.
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