Differentiation of mucinous from non-mucinous pancreatic cyst fluid using dual-stained, 1 dimensional polyacrylamide gel electrophoresis.

BACKGROUND: Pancreatic cysts are being increasingly identified in patients. Mucinous cysts have malignant potential whereas non-mucinous cysts do not. Distinguishing potentially malignant cysts from harmless ones by the characterization of cyst fluid contents remains a difficult problem. This study was undertaken to determine whether cyst fluid mucin glycoprotein analysis could differentiate mucinous from non-mucinous pancreatic cysts. METHODS: Cyst fluid from 28 patients who underwent resection of a pancreatic cyst was used for the study. In each case the type of cyst was histologically identified. One dimensional SDS polyacrylamide gel electrophoresis (1D-SDS PAGE) was performed on cyst fluid samples. For the detection of the separated proteins, we employed a novel dual staining technique. The gel was first stained with periodic acid Schiff (PAS), a mucin histochemical stain followed by a secondary protein staining with Simply Blue Safestain (Invitrogen). RESULTS: Visual scoring (based on the presence of mucins) gave a sensitivity of 95%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 88% for prediction of mucinous histology. CONCLUSIONS: One dimensional SDS polyacrylamide gel electrophoresis of pancreatic cyst fluid, followed by mucin (PAS) and protein (Simply Blue Safestain) staining, provides a means of concentrating and visualizing mucins, which allows the accurate differentiation of mucinous from non-mucinous histology in pancreatic cysts.

Intraprocedural tissue diagnosis during ERCP employing a new cytology preparation of forceps biopsy (Smash protocol).

OBJECTIVES: Techniques of tissue sampling at endoscopic retrograde cholangiopancreatography (ERCP) have been underutilized due to technical demands, low yield, and lack of immediate intraprocedural diagnosis. The objective of this study was to describe a new inexpensive, highly efficient ERCP tissue processing, and interpretation technique to address these issues. METHODS: A retrospective, institutional review board approved, single-center study was done at a tertiary-care medical center. Between June 2004 and February 2009, 133 patients (age 38-95 years; men 53%) with suspicious biliary strictures underwent ERCP with tissue sampling using a new technique. Small forceps biopsy specimens were forcefully smashed between two dry glass slides, immediately fixed, stained with rapid Papanicolaou, and interpreted by an on-site pathologist during the procedure (Smash protocol). RESULTS: Of the 117 proven to have cancer, true-positive Smash preps included pancreatic cancer 49/66 (74%), cholangiocarcinoma 23/29 (79%), metastatic cancer 8/15 (53%), and other 4/7 (57%). The median number of Smash biopsies to diagnosis was 3 (range 1-17). Suspicious or atypical results were considered to be negative in this study. There were no false positives and no complications. Smash had an overall sensitivity of 89/117 (76%) for all cases. The true-positive yield of immediate Smash prep cytology, combined with ERCP fine needle aspirate (FNA) and forceps biopsy histology was 77/95 (81%) for primary pancreaticobiliary cancers. CONCLUSIONS: Immediate cytopathologic diagnosis at ERCP was established in 72% of patients presenting with suspected malignant biliary obstruction using a new cytological preparation of forceps biopsies. This approach to ERCP tissue sampling permits immediate diagnosis and avoids the need for subsequent procedures, adds little cost and time, and is safe to perform.

Success and complications of endoscopic removal of giant duodenal and ampullary polyps: a comparative series.

BACKGROUND: Increasing reports suggest that endoscopic removal of benign ampullary and duodenal polyps is safe and frequently definitive; however, most reported polyps have been small in size (<3 cm). We have developed experience with endoscopic removal of increasingly large and complex polyps. PATIENTS: Fifty-one cases of endoscopic removal were attempted and grouped according to size: group A (n = 22) polyps 1 to 3 cm and group B (n = 29) polyps 3 cm or larger, including 7 cases larger than 5 cm. When the ampulla was involved, biductal sphincterotomy and prophylactic pancreatic duct stent placement was performed first, followed by saline solution-assisted piecemeal polypectomy, argon plasma coagulation, selective endoclip placement, and recovery of all polyp fragments. INTERVENTIONS: Endoscopic removal of duodenal and ampullary adenomas. RESULTS: The outcomes of small and large adenoma removal include mean number of endoscopic retrograde cholangiopancreatographies required for complete removal (2.09 vs 2.56, P = .392), number of complications (4.5% vs 13.9%, P = .375), discovery of unsuspected cancer (0% vs 10.3%, P = .242), and final definitive resolution (100% vs 86.2%, P = .124). Complete removal was achieved in 92.2% of all patients. LIMITATIONS: This was a single center retrospective study. CONCLUSIONS: Large (>/=3 cm) ampullary and duodenal polyps comprised 56.9% of our endoscopically treated cases and present special challenges to definitive endoscopic removal. Successful removal of even very large sessile lesions is possible with minimal increase in risk.