Intraductal Papillary-Mucinous Neoplasm of the Pancreas: The Findings and Limitations of Cytologic Samples Obtained by Endoscopic Ultrasound-Guided Fine-Needle Aspiration

All clinically and ultrasonographically suspected examples of intraductalpapillary-mucinous neoplasm (IPMN) aspirated during a 17-month period were reviewed and analyzed for follow-up. We identified 18 cases of suspected IPMN in patients 52 to 87 years old. All patients had dilated pancreatic ducts, with 3 showing sonographically apparent intraductal papillary lesions; 5 had adjacent cystic or solid pancreatic masses. Cytologic preparations showed thick, glistening, viscid, abnormal mucus in all cases. Aspirates from 13 lesions (72%) were acellular or sparsely cellular, but entrapped single or loosely cohesive neoplastic cells were identified in 16 cases (89%). Goblet cell morphologic features were common (6/18 [33%]), but papillary clusters and dysplastic changes were infrequent (3 [17%] each). In keeping with current therapeutic thinking, confirmatory histologic follow-up was available for only 4 patients (22%), as most people with lesions clinically, sonographically, and cytologically consistent with IPMN are elderly and often have comorbid conditions. Although endoscopic ultrasound-guided fine-needle aspiration has important limitations, gross and cytologic findings can aid in confirming the suspected diagnosis, and integration of complete clinical, sonographic, and cytologic information may be the best way to reach the most accurate diagnosis possible.