Scraping cytology with a guidewire for pancreatic-ductal strictures

Background: Strictures of the pancreatic duct may be caused by a variety of underlying pathologic conditions that imaging examinations often fail to define. Conventional procedures for acquisition of a specimen for cytology during ERCP have been limited in their ability to discriminate pancreatic-ductal strictures. Objective: Our aim was to discriminate pancreatic-ductal strictures by a new technique of sampling material for cytodiagnosis: scraping cytology with a guidewire. Design: A retrospective study. Setting: A single cancer center. Patients and Methods: Eighty-six patients with pancreatic-ductal strictures composed of 71 malignant and 15 benign diseases were evaluated. Malignant diseases included 70 pancreatic carcinomas and 1 endocrine tumor; benign diseases included the following: 7 chronic pancreatitis, 3 autoimmune pancreatitis, 3 idiopathic pancreatic-ductal strictures, and 2 pancreatic cysts. During ERCP, pancreatic juice was collected with a cannula in the main duct just below the stricture after scraping it with a 0.025-inch hydrophilic guidewire. Cytodiagnosis of the specimen was performed by the Papanicolaou method. Main Outcome Measurements: Diagnostic sensitivities and specificities of scraping cytology with a guidewire for pancreatic carcinoma. Results: Scraping cytology with a guidewire yielded 93% sensitivity, 100% specificity, 100% positive predictive value, 75% negative predictive value, and 94% accuracy. Sensitivities for pancreatic carcinoma in the head, body, and tail of the pancreas were 91%, 100%, and 91%, respectively. Sensitivities for pancreatic carcinoma with a tumor of <20 mm, 21 to 40 mm, 41 to 60 mm, and >61 mm were 95%, 92%, 100%, and 100%, respectively. Pancreatitis subsequent to the procedure occurred in 4 patients (5%), all of whom were cured by conservative treatment. Conclusions: Benign or malignant pancreatic-ductal strictures were accurately discriminated by scraping cytology with a guidewire during ERCP. The technique yielded high diagnostic sensitivities in pancreatic carcinoma, regardless of the location or size of the tumor.