Intraductal Papillary Mucinous Neoplasm of the Pancreas: An Update

Abstract

Intraductal papillary mucinous neoplasm (IPMN) is a cystic tumor of the pancreas. The etiology is unknown, but increasing evidence suggests the involvement of several tumorigenesis pathways, including an association with hereditary syndromes. IPMN occurs more commonly in men, with the mean age at diagnosis between 64 and 67 years old. At the time of diagnosis, it may be benign, with or without dysplasia, or frankly malignant with an invasive carcinoma. Tumors arising from the main pancreatic duct are termed main-duct IPMNs, those involving the branch ducts, branch-duct IPMNs. In general, small branch-duct IPMNs are benign, particularly in asymptomatic patients, and can be safely followed. In contrast, main-duct tumors should be surgically resected and examined carefully for an invasive component. In the absence of invasion, patient's survival is excellent, from 94 to 100%. For patients with an IPMN-associated invasive carcinoma, the prognosis overall is better than those with a de novo pancreatic ductal adenocarcinoma, with a 5-year survival of 40% to 60% in some series. However, no survival advantage can be demonstrated if the invasive component in an IPMN patient is that of the conventional tubular type (versus mucinous carcinoma). Several histomorphologic variants are recognized, although the clinical significance of this “subtyping” is not well defined.

Annexin A10 is a candidate marker associated with the progression of pancreatic precursor lesions to adenocarcinoma

“…IPMN of the pancreas is an epithelial neoplasm of mucin producing cells arising in the main or branch ducts [31]. Based on cytoarchitectural atypia, IPMN is classified into low- and high-grade dysplasia [32].…”

The Dilemma of the Dilated Main Pancreatic Duct in the Distal Pancreatic Remnant After Proximal Pancreatectomy for IPMN

“…The most specific (71.4%) clinical indicator of MD-IPMN in the DPR was patient-reported unexplained weight loss, occurring twice as frequently in those with MD-IPMN (57.1%) compared to those with other diagnoses in the DPR (28.6%). While MD-IPMN, mucin, pancreatitis, or stricture of the pancreato-enteric anastomosis may all contribute to ductal obstruction, exocrine insufficiency, and ultimately weight loss, [46] it is unclear why this feature was reportedly more prominent in those with MD-IPMN in the present study. The surgeon was concerned about MD-IPMN in most cases, leading to high sensitivity but poor specificity for MD-IPMN in the DPR.…”

Cyst Features and Risk of Malignancy in Intraductal Papillary Mucinous Neoplasms of the Pancreas: Imaging and Pathology

“…Studies have revealed that IPMNs are more often associated with other nonpancreatic cancer manifestations and are sometimes associated with MSI, MSH2, or MSH6 [ 17 , 18 ] as well as BRCA2 mutations, which were found in 25% of IPMN patients with a family history of pancreatic cancer in a study by Lubezky et al [ 17 ]. Associations with Peutz-Jeghers syndrome have also been described in the literature [ 5 ]. Furthermore, studies examining the rate of extrapancreatic neoplasms have shown that patients with an IPMN have an increased rate of extrapancreatic neoplasms in 3.5–9.3% depending on the follow-up time, the most frequent being colonic, gastric, prostatic, and breast carcinomas [ 2 , 4 , 5 , 16 , 17 , 20 ].…”

“…Regarding potentially malignant cystic pancreatic neoplasms that are lined by a mucinous epithelium, several discriminating criteria evolved during the past years, not least due to improved radiological techniques and thorough pathological workup [ 4 ]. Thus, MCN, which histologically contain an ovarian-like stroma in general, typically do not involve pancreatic ducts, while IPMNs were shown to arise from the pancreatic ductal system [ 1 , 5 , 6 ]. As subsequently described in detail, IPMNs are regarded as premalignant lesions going through a cascade of malignant transformation, starting as IPMN with low-grade dysplasia (also termed adenomas) and possibly progressing into IPMNs with associated invasive carcinoma.…”