Clinical aspects of intraductal papillary mucinous neoplasm of the pancreas

Abstract

Intraductal papillary mucinous neoplasm (IPMN) is a spectrum of neoplasia in the pancreatic duct epithelium characterized by cystic dilation of the main and/or branch pancreatic duct. According to the site of involvement IPMNs are classified into three categories, i.e., main duct type, branch duct type, and combined type. Most branch duct IPMNs are benign, whereas the other two types are often malignant. A large size of branch duct IPMN and marked dilation of the main pancreatic duct indicate the presence of adenoma at least. The additional existence of large mural nodules increases the possibility of malignancy in all types. Of recent interest is the relatively high prevalence of synchronous and/or metachronous malignancy in various organs, including the pancreas. The prognosis is favorable after complete resection of benign and noninvasive malignant IPMNs. Malignant IPMNs acquiring aggressiveness after parenchymal invasion necessitate adequate lymph node dissection. On the other hand, asymptomatic branch duct IPMNs without mural nodules can be observed without resection for a considerably long time. This review addresses available data, current understanding, controversy, and future directions.

Expression of claudin-4 (CLDN4) mRNA in intraductal papillary mucinous neoplasms of the pancreas

“…1 Intraductal papillary mucinous neoplasms are considered to progress sequentially from adenoma to carcinoma in a stepwise fashion. 2 Compared with non-invasive intraductal papillary mucinous neoplasms, invasive carcinomas derived from intraductal papillary mucinous neoplasms have a poor prognosis. 3 Intraductal papillary mucinous neoplasms are also classified into several subtypes based on morphological features and immunohistochemical findings of mucin expression regardless of the histological grade, including gastric type, intestinal type, pancreatobiliary type, and oncocytic type.…”

“…However, intestinal-type intraductal papillary mucinous neoplasms tend to be found in high-grade intraductal papillary mucinous neoplasms of borderline neoplasm and carcinoma, notably colloid carcinoma. 2 According to the International Consensus Guidelines, 6 all main duct intraductal papillary mucinous neoplasms, including mixed type, and branch duct intraductal papillary mucinous neoplasms suspected of malignancy are candidates for surgery. Although some clinical and imaging features, including dilatation of the main pancreatic duct, the presence of intramural nodules, cyst size of more than 30 mm, and the presence of symptoms, have been shown to predict malignancy in intraductal papillary mucinous neoplasms, it is sometimes difficult to accurately diagnose the grade of malignancy of intraductal papillary mucinous neoplasms preoperatively by these predictors.…”

REG4 is associated with carcinogenesis in the ‘intestinal’ pathway of intraductal papillary mucinous neoplasms

“…Intraductal papillary mucinous neoplasms (IPMNs) show a wide spectrum of histological differentiation from hyperplasia, adenoma and borderline neoplasm to carcinoma, and the existence of an adenoma-carcinoma sequence is documented. [1][2][3] IPMNs are considered to be precursors of invasive cancer of either tubular ductal adenocarcinoma or colloid (mucinous noncystic) carcinoma. [4][5][6][7] Recently, subclassification of IPMNs, based on morphological features and immunohistochemical profiles, has been proposed.…”

“…[8][9][10] IPMNs arising from branch ducts often show gastric-type differentiation and have a less aggressive clinical course. 1,9 Pancreatobiliary-type IPMNs show severe atypia corresponding to in situ carcinoma and is often associated with an invasive tubular type of ductal adenocarcinoma. These findings suggest that each type of IPMN follows a different pathway of carcinogenesis.…”

“…20 Nonsurgical management with close observation is recommended for branch duct IPMNs without high-risk criteria such as mural nodules. 1,20,21 However, there is a possibility that even branch duct IPMNs, without high-risk criteria, may include high-grade malignant lesions. 22 We also analyzed REG4 expression according to IPMN location: branch limited, mixed and main duct type.…”