Objective: The accuracy of endoscopic ultrasonography (EUS) and EUS-guided fine-needle aspiration for the differential diagnosis of pancreatic masses is variable in the literature, being as low as 75% in some studies. The aim of the study was to assess the accuracy of power Doppler EUS for the differential diagnosis between pancreatic cancer and pseudotumoral chronic pancreatitis.
Methods: We included 42 consecutive patients with pancreatic tumor masses (27 men and 15 women) examined by EUS between January 2002 and August 2004. Endoscopic ultrasonographic procedures included power Doppler EUS as well as EUS-guided fine-needle aspiration in all patients. Final diagnosis of pancreatic cancer was confirmed in 29 patients on the basis of a combination of information provided by imaging tests, follow-up of at least 6 months, and laparotomy in 18 patients for diagnostic or palliative reasons.
Results: Sensitivity and specificity of the absence of power Doppler signals inside the suggestive pancreatic mass were 93% and 77%, respectively, with accuracy of 88%. Moreover, the addition of the information provided by the presence of peripancreatic collaterals improved the sensitivity and specificity to 97% and 92%, with accuracy of 95%.
Conclusions: Power Doppler EUS provides useful information for the differential diagnosis of pancreatic masses. The results were in concordance with previous studies that showed a hypovascular pattern of pancreatic carcinoma, as well as the formation of collaterals in advanced cases due to the invasion of the splenic or portal veins. Further studies of dynamic EUS with contrast agents are necessary to better characterize pancreatic masses.