UTILITY OF POWER DOPPLER ENDOSCOPIC ULTRASOUND FOR THE DIFFERENTIAL DIAGNOSIS BETWEEN PANCREATIC CANCER AND PSEUDOTUMORAL CHRONIC PANCREATITIS

Purpose: Endoscopic ultrasound (EUS) coupled with fine needle aspiration biopsy (EUS-FNA) are very useful for the detection of pancreatic tumors, for the differential diagnosis between benign and malignant tumors, as well as for staging and resecability. However, the accuracy of EUS and EUS-FNA for the differential diagnosis of pancreatic masses are variable in the literature, being as low as 75% in some studies.

Methods and Materials: Our study included 42 consecutive patients with a clinical suspicion of pancreatic tumor mass (27 men and 15 women), examined by EUS, between january 2002 and august 2004. EUS procedures included color and power Doppler, as well as EUS-FNA in all patients. Final diagnosis of pancreatic cancer was confirmed in 29 patients based on a combination of information provided by imaging tests, clinical follow-up of 6 months, as well as laparotomy in 18 patients for diagnostic or paleative reasons.

Results: Sensitivity and specificity of the absence of power Doppler signals inside the suspicious pancreatic mass were 93% and 77%, with an accuracy of 88% for the diagnosis of pancreatic cancer. Moreover, the addition of the information provided by the presence of peripancreatic or periduodenal collaterals improved the sensitivity and specificity to 97% and 92%, with an accuracy of 95%.

Conclusions: In conclusion, power Doppler EUS provides useful information for the differential diagnosis of pancreatic masses. The results of our study are in concordance with previous studies that demonstrated 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.