Case ReviewsNoninvasive and Minimally Invasive Intraductal Papillary Mucinous Neoplasms of the PancreasFurukawa, Toru MD, PhD*; Hatori, Takashi MD, PhD†; Nagao, Kenta MD†; Kuboki, Yuko MD†; Hira, Yuko MD†; Tahara, Junko MD, PhD†; Takayama, Yukiko MD, PhD†; Shimizu, Kyoko MD, PhD†; Kimijima, Akira MD†; Kobayashi, Makio MD, PhD‡; Yamamoto, Masakazu MD, PhD†; Shiratori, Keiko MD, PhD†Author Information From the *International Research and Educational Institute for Integrated Medical Sciences, †Institute of Gastroenterology, and ‡Department of Pathology, Tokyo Women's Medical University, Tokyo, Japan. Reprints: Toru Furukawa, MD, PhD, Institute for Integrated Medical Sciences, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan. E-mail: [email protected]. Toru Furukawa is supported by the Program for Promoting the Establishment of Strategic Research Centers, Special Coordination Funds for Promoting Science and Technology, Ministry of Education, Culture, Sports, Science and Technology, Tokyo, Japan. Pathology Case Reviews: November-December 2010 - Volume 15 - Issue 6 - p 183-187 doi: 10.1097/PCR.0b013e3181ffa907 Buy Metrics Abstract Intraductal papillary mucinous neoplasms of the pancreas are characterized by mucinous dilatation of the duct lined with neoplastic cells forming papillae. Noninvasive intraductal papillary mucinous neoplasms are classified into low-, moderate-, or high-grade dysplasia. The epithelium of the papillae exhibits 4 morphologically distinct types-gastric, intestinal, pancreaticobiliary, and oncocytic-with specific expressions of mucin glycoproteins. Intraductal papillary mucinous neoplasms with low-grade dysplasia comprise papillae resembling gastric foveolae or pyloric glands; those with moderate dysplasia usually comprise papillae exhibiting intestinal features. High-grade intraductal papillary mucinous neoplasms of gastric type exhibit short, complex, and irregular shapes of papillae with highly atypical nuclei. High-grade intraductal papillary mucinous neoplasms of the intestinal type exhibit large villous papillae composed of tall columnar cells with enlarged atypical nuclei, basophilic cytoplasm, and abundant acid mucin; those of the pancreaticobiliary type exhibit fern leaf-like thin branching complex papillae composed of cells with amphophilic to basophilic cytoplasm and high nucleus-to-cytoplasmic ratios. High-grade intraductal papillary mucinous neoplasms of the oncocytic type exhibit arborizing papillae composed of eosinophilic cells containing enlarged round nuclei with prominent nucleoli. Intraductal papillary mucinous neoplasms with minimal invasion have invasion slightly beyond the duct wall. Invasive foci within a 5-mm distance from involved ducts may be a practical criterion for assessing minimal invasion. Patients with low- or moderate-grade intraductal papillary mucinous neoplasms show a fairly good prognosis; almost no patients died owing to the neoplasm. However, patients with high-grade neoplasms and those with minimally invasive neoplasms may show an unfavorable prognosis, with 5-year survival rates of 94% to 98% and 89% to 91%, respectively. © 2010 Lippincott Williams & Wilkins, Inc.