Usefulness of cell block cytology for preoperative grading and typing of intraductal papillary mucinous neoplasms

BackgroundPrecise histological diagnosis is important for the successful management of intraductal papillary mucinous neoplasms (IPMNs).ObjectThe object of this study was to determine whether cell block cytology is useful for preoperative cytomorphological grading and typing of IPMNs.MethodsThe subjects were 23 patients with IPMN from whom pancreatic juice was collected via a pancreatic catheter and who subsequently underwent pancreatic resection.ResultsIn 20 of the 23 cases, the quantity of cells collected for cell block cytology was sufficient to enable typing and grading of the IPMN. The rates of consistency between the results of typing and grading by cell block cytology and histological examination of the surgical specimen were 95% and 80%, respectively. Typing of the 10 main-duct/mixed-duct-type IPMNs by cell block cytology yielded 5 gastric types, 3 intestinal types, 1 oncocytic type, and 1 pancreatobiliary type, and the typing was consistent with the surgical diagnosis in all 10 cases. The results of typing of the branch-duct-type IPMNs by cell block cytology were identical to the results of histological typing in the surgical specimens in every case but one. However, the specificity of cell block cytology for grading IPMNs was 55.6%.ConclusionsThe cell block cytological findings were fairly consistent with the histopathological features of the surgical specimens, thereby indicating that cell block cytology may be useful for preoperative and typing of IPMNs, but only play a supplementary role in grading IPMNs.