Brendan Visser MD, PRESENTER: Nothing to Disclose

Abstract: HTML Purpose: To determine the relative accuracy of CT and MR imaging in the characterization of cystic pancreatic masses as benign or malignant. Methods and Materials: We retrospectively identified 54 patients with cystic pancreatic masses who underwent CT (n = 34) or MR imaging (n = 4) or both (n = 13) between 1997 and 2003, and in whom a definitive diagnosis was established by subsequent resection (n = 47) or biopsy (n = 7). Two readers independently reviewed CT and MR images at separate sessions, and recorded both morphologic tumor characteristics and the overall likelihood of malignancy. Receiver-operating characteristic curve analysis was performed. In addition, the frequency of malignancy in small (4 cm or less in diameter), unilocular, thin-walled (3 mm or less in thickness) lesions was specifically investigated. Results: The final histopathologic diagnoses were mucinous cystadenoma (n = 10), serous cystadenoma (n = 8), mucinous cystadenocarcinoma (n = 7), pseudocyst (n = 7), intraductal papillary mucinous tumor (n = 5), cystic ductal adenocarcinoma (n = 4), simple cyst (n = 4), cystic neuroendocrine tumor (n = 3), and miscellaneous (n = 6). Overall, 20 of 54 (37%) masses were malignant. For mass characterization as benign or malignant by reader 1 (reader 2), receiver-operating characteristic curve analysis showed an area under the curve of 0.82 (0.74) for CT (p= 0.001 and 0.01, for readers 1 and 2, respectively) and 0.82 (0.75) for MR imaging (p=0.07 and 0.15). Two of 10 (20%) small, unilocular and thin walled masses were malignant. Conclusion: CT and MR imaging are of reasonable and similar accuracy in the differentiation of benign from malignant cystic pancreatic masses; a notable limitation of both modalities is that a substantial fraction of morphologically benign-appearing cystic pancreatic masses are malignant.      

Visser MD, B, Relative Accuracy of CT and MR Imaging in the Characterization of Cystic Pancreatic Masses.  Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL. http://archive.rsna.org/2003/3108298.html