Differential diagnosis of solid pancreatic masses: contrast-enhanced harmonic (CEH-EUS), quantitative-elastography (QE-EUS), or both?
BACKGROUND
Contrast-enhanced harmonic endoscopic ultrasound (CEH-EUS) and quantitative-elastography endoscopic ultrasound (QE-EUS) are considered useful tools for the evaluation of solid pancreatic tumors (SPT). The aim of our study was to evaluate the diagnostic accuracy of CEH-EUS, QE-EUS, and the combination of both for the differential diagnosis of SPT.


METHODS
Sixty-two consecutive patients (mean age 64.3 years, range 32-89 years, 44 male) who underwent EUS for the evaluation of SPT were prospectively included. EUS was performed with a linear Pentax-EUS and a Hitachi-Preirus processor. The mass (area A) and a reference area B were selected during QE-EUS, and results expressed as B/A (strain ratio). A strain histogram of the mass was also evaluated. Microvascularization of the tumor was evaluated over 2 min during CEH-EUS after intravenous injection of 4.8 mL SonoVue. Final diagnosis was based on histopathology of surgical specimens or EUS-guided tissue acquisition and clinical follow-up in non-operated cases. Diagnostic accuracy of CEH-EUS, QE-EUS, and their combination was calculated.


RESULTS
Median size of the masses was 32 mm (range 12-111). Final diagnosis was pancreatic adenocarcinoma (n= 45), neuroendocrine tumor (n= 3), inflammatory mass (n= 10), pancreatic metastasis (n= 2), autoimmune pancreatitis (n= 1), and a mucinous cystadenocarcinoma (n= 1). Overall accuracies for determination of malignancy using QE-EUS, CEH-EUS, their combination, and EUS-guided tissue acquisition were 98.4% (95% confidence interval (CI): 91.4-99.7), 85.5% (95% CI: 74.7-92.2), 91.9% (95% CI: 82.5-96.5), and 91.5% (95% CI: 83.6-99.5), respectively.


CONCLUSIONS
The combination of QE-EUS and CEH-EUS is a useful tool for the differential diagnosis of SPT, giving complementary information. However, this combination does not significantly increase the diagnostic accuracy of either of the techniques performed alone.
Department of Gastroenterology and Instituto de Investigación Sanitaria de Santiago (IDIS), University Hospital of Santiago de Compostela, Santiago de Compostela, Spain.
Julio
J
Iglesias-Garcia
Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
Björn
B
Lindkvist
Department of Gastroenterology and Instituto de Investigación Sanitaria de Santiago (IDIS), University Hospital of Santiago de Compostela, Santiago de Compostela, Spain.
Jose
J
Lariño-Noia
Department of Pathology, University Hospital of Santiago de Compostela, Santiago de Compostela, Spain.
Ihab
I
Abdulkader-Nallib
Department of Gastroenterology and Instituto de Investigación Sanitaria de Santiago (IDIS), University Hospital of Santiago de Compostela, Santiago de Compostela, Spain.
J Enrique
JE
Dominguez-Muñoz
Solid pancreatic lesion; endoscopic ultrasound; stiffness; tissue acquisition; vascularization