Abstract

Intraductal Papillary Mucinous Neoplasm of the Pancreas

Author(s): Jayalatha Nethagani1, Priyanka Govula2, Revathi Chandu3, Pravin Raj T.4

Pancreatic cancer is the fourth most common cause of
cancer-related mortality worldwide, with an incidence rate
equalling that of its mortality rate.1 There are numerous
primary pancreatic neoplasms, in part due to the mixed
endocrine and exocrine components. Previously thought to
be rare, intraductal papillary mucinous neoplasms (IPMNs)
now constitute 20 - 30 % of pancreatic cystic neoplasms.2
IPMN is similar to chronic pancreatitis in presentation with
symptoms such as relapsing abdominal pain, steatorrhea,
pancreatitis and radiological findings of cystic lesions
communicating with dilated pancreatic duct that can be
misdiagnosed as chronic pancreatitis with pseudocysts.
Pancreatic pseudocyst may simulate clinically and
radiologically with other cystic neoplasms of the pancreas.3
IPMNs have been classified as branch duct (BD) type,
main duct (MD) type, and combined or mixed type based on
imaging findings. Computed tomography (CT) and magnetic
resonance imaging (MRI), along with magnetic resonance
cholangiopancreatography, are the most useful radiologic
methods for detecting IPMNs.4 Moreover, these imaging
modalities are useful in distinguishing BD-IPMNs from other
cystic lesions by showing multiplicity and a connection to the
main pancreatic duct (MPD). Study results showed that MR
imaging with MRCP showed acceptable diagnostic
performance in the prediction of the malignant potential of
IPMNs when using the image criteria of the international
consensus guidelines 2012.5
There has been significant increase in the incidence of
IPMN in the last decade and this increase is most likely due
to a combination of factors.6,3 The grouping of previously
autonomous tumours, such as mucin producing tumours of
the pancreas, papillary carcinomas and villous adenoma, as
well as improved diagnostic imaging undoubtedly has a
central role here.6,3 Although thought to be benign
pancreatic IPMN is potential preneoplastic cystic lesion of the
pancreas with a number of radiological findings that favour
malignancy called as “worrisome feature” and “high-risk
stigmata” groups.7 Four subtypes of IPMN are currently
recognized: gastric, intestinal, oncocytic and pancreaticobiliary.
This carcinoma resembles conventional ductal
adenocarcinoma in both morphology, diagnosis and
prognosis. The classical type of malignancy accompanying
IPMN is pancreatic ductal adenocarcinoma (PDAC). The
frequency of PDAC occurrence has been reported with a
spectrum of 1.9 – 9.2 % in different literature data.