Background: Endoscopic ultrasound (EUS) is a modern
modality aids in the diagnosis and treatment of pancreatic and
biliary diseases. It also allows tissue sampling and staging. AIM:
To compare the diagnostic accuracy of Endoscopic
Ultrasonography (EUS) guided fine needle aspiration (FNA)
before and after biliary decompression in suspected
pancreaticobiliary malignancy. Patients and Methods: This
prospective cross-sectional study was conducted in Tanta
University (internal medicine department) and Benha University
(hepatology, gastroenterology and infectious disease department)
on (120) patients with suspected pancreaticobiliary malignancy
referred for EUS evaluation with or without fine needle
aspiration (FNA). And they classified into two groups based on
the presence or absence of biliary stent. All patients included in
this study subjected to: Complete history taking and thorough
clinical examination, laboratory investigations (Complete blood
picture, liver profile, CA19-9), imaging (Pelvi abdominal
ultrasonography (US) and or, Abdominal triphasic CT scan and
or, Magnetic Resonance Cholangiopancreatography (MRCP),
endoscope (Endoscopic ultrasound (E.U.S). Results: Comparing
between both groups using the univariate regression analysis,
increasing the tumor size, increasing the number of passes and
use of 22-guage needle were shown as predictors associated with
accurate diagnosis by EUS. However, with application of
multivariate regression analysis, increasing the tumor size and
use of 22-guage needle were shown as independent predictors
associated with accurate diagnosis by EUS. the presence of stent
did not influence the accuracy of diagnosis.Conclusion:Pre-EUS
stenting of biliary obstruction due to pancreaticobiliary
malignancy didn’t influence the rate of tissue diagnosis.