Intraductal neoplasms of the pancreas: an update

Abstract

ABStRACtwith improvements in imaging to detect silent pancreatic lesions and increases in the number of centers now performing pancreatic surgery, more surgeries have been performed for indications other than invasive carcinoma. This has enormously added to our knowledge of the intraductal neoplasms of the pancreas. In addition, our understanding of the genetics of these lesions has expanded with the introduction of routine molecular genetic analyses. In this review, we provide an update into the most common intraductal neoplasms, namely intraductal papillary mucinous neoplasm and intraductal tubulopapillary neoplasm. we first focus on their clinicopathologic and molecular features of relevance to the practicing pathologist and then discuss their differential diagnoses.

Type 1 Autoimmune Pancreatitis Extending along the Main Pancreatic Duct: IgG4-related Pancreatic Periductitis

“…The EUS findings showed the mass component to be mostly within and along the MPD, suggesting curable ductal neoplasms; therefore, a fine-needle aspiration biopsy was not performed due to the risk of seeding (12). Of course, atypical images of pancreatic ductal adenocarcinoma or IPMN (less the mucinsecreting type) could not be denied; however, intraductal neoplasms, such as intraductal tubular neoplasm, intraductal tubulopapillary neoplasm (13,14), and acinar cell carcinoma (15), were suspected based on the EUS images. Thus far, cases of AIP mimicking malignant IPMN have been reported, showing nodular lesions protruding inside the MPD (7) or branch duct (5,9), as well as wall thickening around the multilocular cyst (8).…”

Undifferentiated carcinoma of the pancreas with osteoclast-like giant cells showing intraductal growth and intratumoral hemorrhage: MRI features

“…Recently, Muraki et al revealed that UCPOGC often show intraductal growth pattern (40%), which may suggest relatively indolent biological behavior of this entity [3], [7]. Differential diagnosis of tumors exhibiting this peculiar growth pattern includes intraductal papillo-tubular neoplasm, and intraductal papillary mucinous neoplasms (MD type), and NET, but small number of cases of acinar cell carcinoma and UCPOGC have been reported as well [1], [3], [4], [5], [15], [16], [17]. Because the lesion in the current report was apparently hypervascular, our preoperative diagnosis of NET was made.…”

Intraductal neoplasms of the pancreatobiliary tract: navigating the alphabet

“…17 Depending on the pancreatic ducts affected, IPMNs can be divided into three groups: (i) main-duct IPMNs (the main pancreatic duct is involved); (ii) branchduct IPMNs (the branches of the main duct are involved); and (iii) mixed IPMNs (the main pancreatic duct and its branches are involved). 3,18,19 This classification is of clinical importance, as it has value in pre-operative algorithms (the main duct IPMNs have a greater risk of revealing high-grade dysplasia or invasive carcinoma). 3,20 However, its significance is over-ridden once the tumour is resected as the presence of invasion and dysplasia grade becomes more important.…”