Evaluation of Pancreatic Cystic Lesions Via EUS-guided Fine Needle Aspiration With and Without Micro Forceps Biopsies

Pancreatic cystic lesions (PCLs) are a common incidental finding in cross sectional imaging (up to 27% on CT scan and 41% on MRI) and pose a management challenge to physicians. According to society guidelines, PCLs with specific features should prompt additional workup with endoscopic ultrasound (EUS) for cyst characterization as well as cyst sampling. This can help determine if the cyst is mucinous or non-mucinous which has implications for its malignant potential. Cyst fluid has traditionally been sampled using EUS with fine needle aspiration (EUS-FNA) and sent for fluid analysis and cytology. More recently, the adjunctive use of the through-the-scope micro forceps (Moray micro forceps, US Endoscopy, Mentor, OH) biopsy (EUS-MFB) has shown promise for diagnosis of PCLs. This technology utilizes a micro forceps through a 19-gauge needle to biopsy the cyst wall for histology, in addition to collecting cyst fluid for CEA level and cytology. More recently, the adjunctive use of the Moray® through the needle micro forceps biopsy (EUS-MFB) has shown promise for diagnosis of PCLs. This technology utilizes a micro forceps through a 19-gauge needle to biopsy the cyst wall for histology, in addition to collecting cyst fluid for CEA level and cytology. Only a few small retrospective reports have been published regarding the use of MFB. The results of this study will hopefully help increase diagnostic yield by obtaining a histopathologic diagnosis of these PCLs, and potentially affect practice patterns of gastroenterologists and the endoscopic community, specifically those physicians who perform EUS in these patients. Furthermore, the results will help determine whether there is reason to continue this line of research to obtain a definite histologic tissue diagnosis of PCLs.

Pancreatic cystic lesions (PCLs) are a common incidental finding in cross sectional imaging (up to 27% on CT scan and 41% on MRI) and pose a management challenge to physicians. According to society guidelines, PCLs with specific features should prompt additional workup with endoscopic ultrasound (EUS) for cyst characterization as well as cyst sampling. This can help determine if the cyst is mucinous or non-mucinous which has implications for its malignant potential. Cyst fluid has traditionally been sampled using EUS with FNA (Fine-Needle Aspiration) and sent for fluid analysis (CEA and amylase) and cytology. However, despite use of a cyst fluid carcinoembryonic antigen (CEA) level cutoff of 192 ng/mL and cytology, accuracy of diagnosis for PCLs is poor. As the spectrum ranges from benign to high risk for neoplasm, precise diagnosis is critical. More recently, the adjunctive use of the Moray® through the needle micro forceps biopsy (EUS-MFB) has shown promise for diagnosis of PCLs. This technology utilizes a micro forceps through a 19-gauge needle to biopsy the cyst wall for histology, in addition to collecting cyst fluid for CEA level and cytology. Only a few small retrospective reports have been published regarding the use of MFB. Pancreatic cysts continue to pose a management dilemma for practicing clinicians, especially with the increased use of radiologic imaging modalities identifying incidental pancreatic cystic lesions with higher frequency. This leads to patient anxiety and increased costs due to radiologic surveillance and even surgery. The results of this study will hopefully help increase diagnostic yield by obtaining a histopathologic diagnosis of these PCLs, and potentially affect practice patterns of gastroenterologists and the endoscopic community, specifically those physicians who perform EUS in these patients. Furthermore, the results will help determine whether there is reason to continue this line of research to obtain a definite histologic tissue diagnosis of PCLs.

Eligibility Criteria:
Inclusion Criteria:

* Adult patients \>18 years old
* Cysts \> 20 mm in size deemed appropriate for FNA by the endoscopist, based on clinical presentation, radiologic imaging features, associated solid mass or nodules, and patient anxiety about the diagnosis

Exclusion Criteria:

* Age \<18 years
* Inability to provide informed consent
* Thrombocytopenia (Platelets \< 50,000) or coagulopathy (INR \> 1.8)
* Pregnancy
* Post-surgical anatomy where the cyst is not accessible for FNA
* EUS findings suggesting that cyst FNA would be unsafe (e.g. intervening blood vessels)
* EUS appearance suggesting FNA is not indicated (e.g. cyst smaller than prior radiologic imaging, cyst not seen, EUS suggestive of serous cystadenoma)