Endoscopic ultrasound fine-needle aspiration characteristics of primary adenocarcinoma versus other malignant neoplasms of the pancreas.

BACKGROUND: Endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) is often used to assist in the evaluation of pancreatic lesions and may help to diagnose benign versus malignant neoplasms. However, there is a paucity of literature regarding comparative EUS characteristics of various malignant pancreatic neoplasms (primary and metastatic). OBJECTIVE: To compare and characterize primary pancreatic adenocarcinoma versus other malignant neoplasms, hereafter referred to as nonprimary pancreatic adenocarcinoma (NPPA), diagnosed by EUS-guided FNA. METHODS: The present study was a retrospective analysis of a prospectively maintained database. The setting was a tertiary care, academic medical centre. Patients referred for suspected pancreatic neoplasms were evaluated. Based on EUS-FNA characteristics, primary pancreatic adenocarcinoma was differentiated from other malignant neoplasms. The subset of other neoplasms was defined as malignant lesions that were 'NPPAs' (ie, predominantly solid or solid/cystic based on EUS appearance and primary malignant lesions or metastatic lesions to the pancreas). Pancreatic masses that were benign cystic lesions (pseudocyst, simple cyst, serous cystadenoma) and focal inflammatory lesions (acute, chronic and autoimmune pancreatitis) were excluded. RESULTS: A total of 230 patients were evaluated using EUS-FNA for suspected pancreatic mass lesions. Thirty-eight patients were excluded because they were diagnosed with inflammatory lesions or had purely benign cysts. One hundred ninety-two patients had confirmed malignant pancreatic neoplasms (ie, pancreatic adenocarcinoma [n=144], NPPA [n=48]). When comparing adenocarcinoma with NPPA lesions, there was no significant difference in mean age (P=0.0675), sex (P=0.3595) or average lesion size (P=0.3801). On average, four FNA passes were necessary to establish a cytological diagnosis in both lesion subtypes (P=0.396). Adenocarcinomas were more likely to be located in the pancreatic head (P=0.0198), whereas masses in the tail were more likely to be NPPAs (P=0.0006). Adenocarcinomas were also more likely to exhibit vascular invasion (OR 4.37; P=0.0011), malignant lymphadenopathy (P=0.0006), pancreatic duct dilation (OR 2.4; P=0.022) and common bile duct dilation (OR 2.87; P=0.039). CONCLUSIONS: Adenocarcinoma was more likely to be present in the head of the pancreas, have lymph node and vascular involvement, as well as evidence of pancreatic duct and common bile duct obstruction. Of all malignant pancreatic lesions analyzed by EUS-FNA, 25% were NPPA, suggesting that FNA is crucial in establishing a diagnosis and may be helpful in preoperative planning.

Prospective blinded comparison of polyp size on computed tomography colonography and endoscopic colonoscopy.

BACKGROUND & AIMS: The size of polyps found on computed tomography colonography (CTC) has been suggested as the major determinant of patient management. We compared polyp size as seen on CTC with endoscopic visualization, in vivo probe measurement, and ex vivo size before and after fixation. METHODS: Polyps measured on CTC sent for endoscopic removal were evaluated for polyp size in a blinded fashion by endoscopic estimation, in vivo probe measurement, and after removal. RESULTS: Fifty-six polyps were included in the study. There was no significant difference between CTC polyp size, real-time colonoscopy size estimation, or probe measurement. The size of polyp measured immediately ex vivo and after pathology fixation was significantly smaller. Management would be altered in 6 of 56 polyps (10.7%) on the basis of differences between size of the polyp on endoscopy and CTC. CONCLUSIONS: (1) CTC polyp size measurement is not significantly different from colonoscopy in vivo visual estimation and linear probe measurement. (2) Differences in size of polyps as measured on CTC and endoscopy will affect patient management in 10% of cases.

Findings on optical colonoscopy after positive CT colonography exam.

BACKGROUND & AIMS: The aim of this study is to evaluate the findings on optical colonoscopy (OC) after a positive CT colonography (CTC) exam and characterize the type of polyps seen on OC but not reported by CTC. METHODS: Over an 18-month period a total of 159 asymptomatic adults had polyps seen on computed tomography colonography examination and subsequently underwent planned therapeutic optical colonoscopy. The colonoscopists were aware of the findings on CT colonography prior to further evaluation of the colon. Characteristics of polyps and adenomas seen on subsequent optical colonoscopy but not seen or reported on CT colonography were examined. RESULTS: The adenoma miss rate for CT colonography overall was 18.9% (25/132) including 6.2% (4/65) for polyps >9 mm and 18.2% (8/44) for polyps 6-9 mm. Three of the adenomas >9 mm not seen on CTC were sessile, and two were found in patients with technically difficult CT colonography studies due to poor colonic distention. No adenomas with advanced pathology <6 mm were found on optical colonoscopy but not reported on CT colonography. False-positive CTC referral where no polyp was seen on colonoscopy was 5.0%. CONCLUSIONS: CT colonography has adenoma miss rates similar to miss rates historically found with optical colonoscopy, with most missed adenomas being <10 mm and sessile in shape.