The Role of Real Time Endoscopic Ultrasound Guided Elastography for Targeting EUS-FNA of Suspicious Pancreatic Masses: A Review of the Literature and A Single Center Experience.

Background: Endoscopic ultrasound guided elastography is an imaging modality that can be used to evaluate tissue stiffness and to assess solid pancreatic lesions. It can also assist in optimizing the diagnostic yield of endoscopic ultrasound guided fine needle aspiration biopsies.

Aims: To review the literature on solid pancreatic lesions, the use of EUS guided fine needle aspiration and endoscopic ultrasound guided elastography and to present a single center experience using elastography to direct fine needle aspiration biopsies of solid pancreatic lesions.

Methods: We present a review of the literature and a single center experience describing the use of EUS guided elastography in directing fine needle aspiration biopsies of solid pancreatic lesions.

Results: Thirteen male veterans with an average age of 62.3 (SD±11.8) years were enrolled in the study. The mean pancreatic mass size on EUS was 5.1×5.2 (SD±4.4×4.5) cm. A total of 13 lesions were identified during elastography. The lesions were most commonly found in the body (n=5), followed by multifocal lesions (n=4), pancreatic head (n=3) and tail (n=1). The seven concerning pancreatic lesions were stratified based on color pattern identified on EUS and EUS-elastography. Three lesions were homogenously blue, and four lesions were heterogeneously blue. The remaining six lesions which were less concerning were predominantly green. Of the three lesions, that were homogenously blue, two were diagnosed as adenocarcinoma (n=2) and chronic pancreatitis (n=1) respectively. Of the four heterogeneously blue lesions two were adenocarcinomas, while the other two represented a large B-cell lymphoma and chronic pancreatitis. Patients whose lesions were characterized as homogenous or heterogeneous green were benign and remained disease free after a median of two years of regular follow up.

Limitations: Relatively small number of patients studied.

Conclusions: In our single center experience we found that the use of real time endoscopic ultrasound guided elastography for targeting fine needle aspiration of suspicious pancreatic lesions may be beneficial as an adjunct modality to complement conventional EUS. Larger prospective studies need to be conducted to evaluate the utility of this modality in targeting pancreatic lesions.