Immediate Tissue Diagnosis During Ercp Using A New Simple Forceps Biopsy Cytologic Preparation: Technique, Yield and Outcome

Background: Tissue sampling at ERCP has been hampered by technical difficulties, low yield and delay in diagnosis due to specimen processing. EUS with FNA and in-room cytologist addresses these problems, but often adds an additional procedure with increased costs and slight risk. Intraprocedural processing and interpretation of high-yield forceps biopsies (FBs) during ERCP may solve these shortcomings. We present our expanded experience. Methods: From 6/04-7/06, 74 pts with suspicious biliary strictures (BS) were sampled at ERCP using a new technique as follows: Immediately after insertion of a guidewire through the BS a cytology team was summoned, sphincterotomy was performed, and 5 or 6Fr FBs were collected from the lower aspect of the BS. Specimens were forcefully smashed between two dry glass slides, immediately fixed and stained with rapid Papanicolau (SMASH prep). Repeated biopsies were obtained until a diagnosis could be made or 10 or more negatives were noted. Further efforts at tissue sampling using a 22 gauge ERCP needle (HBAN22, Cook Endoscopy) and brush were then attempted. Additional FBs after a positive smear or multiple negatives were submitted for histology. Results: For the purpose of this study, suspicious or atypical results were considered negative. Immediate cytological diagnosis was made in 52/68 (77%) of cases eventually proven to have malignancy. The 49/68 (72%) true positive SMASH preps included: pancreatic cancer 29/37 (78%), cholangioca 13/16 (81%), and metastatic ca 7/15 (47%). FNA added 3/19 (16%) of remaining cancer pts, but brush added none. Median SMASH preps to diagnosis were 2 (range 1-14). Finally, histology confirmed diagnosis in 31 and identified an additional 2 pts who had otherwise negative in-room studies for total ERCP tissue diagnosis of 47/53 (89%) of pancreaticobiliary cancers. Of false negative pts, 3/14 (21%) had tissue diagnosis at EUS and 11/14 (79%) had other invasive biopsies or were treated without tissue confirmation. There were no false positives and no complications. Conclusions: Immediate cytological diagnosis at ERCP was established in 72% of patients presenting with suspected malignant biliary obstruction using a new cytological preparation of forceps biopsies. The positive yield of immediate SMASH prep cytology combined with ERCP FNA and forceps biopsy histology approaches 90% for primary pancreaticobiliary cancers. This approach to ERCP tissue sampling permits immediate and appropriate stent selection, avoids the need for subsequent procedures, adds little cost, and is safe to perform. Patients with metastatic disease producing biliary obstruction are better sampled using EUS guidance.