Imaging of Pancreatic Cystic Lesions

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Imaging of Pancreatic Cystic Lesions
Dr Zaghouani. H, Pr Kraiem Ch Service dimagerie
Farhat Hached
5th ARC of PAARS 6th annuel Meeting of
PAIRS 25-28 April Hammamet
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INTRODUCTION

• Incidence of pancreatic cystic lesions ranges
  from 1 to 25 in various studies incidence in
  asymptomatic general populations is about 2.6.
• Wide spectrum of lesions including, non
  neoplastic, benign, borderline, and malignant
  pathologies.
• Radiologists play an important role in
  detection, characterization, and follow-up of
  cystic lesions of the pancreas.

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Clinical Presentation

• A large number of pancreatic cysts are
  incidentally detected during imaging work-up for
  an unrelated medical problem.

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Epidemiologic characteristics
Brugge WR Eng J Med 2004
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Morphologic Classification of Cystic Pancreatic
Lesions
Radiographics 2005 Nov-Dec25(6)1471-84
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Unilocular Cysts

• Pseudocyst
• IPMN occasionally
• Unilocular serous cystadenoma
• Lymphoepithelial cyst
• Multiple
• Von Hippel-Lindau, Polycystic kidney disease

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Pseudocyst

• Generally symptomatic ( pain)
• If asymptomatic, think about another Dx
• History of acute or chronic pancreatitis
• Almost always pseudocyst with this history
• Look for associated findings
• Pancreatic inflammation, parenchymal
  calcifications, atrophy, typical intraductal
  calcifications
• Can communicate with pancreatic duct
• Wide neck vs. narrow neck for IPMN
• Wall can calcify
• No mural nodules

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Traumatic pseudocyst
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Unilocular serous cystadenoma

• When there is a unilocular cyst with a lobulated
  contour located in the head of the pancreas
  unilocular macrocystic serous cystadenoma.

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Side-branch IPMN manifesting as a unilocular cyst
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Multiple unilocular cysts in a patient withvon
HippelLindau disease
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Microcystic Lesions

• Serous cystadenoma
• Only lesion included in this category
• Benign tumor
• Grandmother Lesion
• May grow up to approx 4 mm/year
• 70 cases demonstrate
• Polycystic/microcystic pattern
• Collection of cysts (gt6)
• Range few mm 2 cm
• External lobulations
• Enhancing septa, walls
• 30 demonstrate fibrous central
• scar /- stellate calcifcation
• Other variants of these tumors
• (macrocystic oligocystic)

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Serous cystadenoma MRI
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• MR imaging the microcysts discrete foci with
  bright signal intensity on T2-weighted images.
• Endoscopic US can help accurately depict these
  small microcysts as discrete small anechoic
  Areas.

Radiographics 2005 Nov-Dec25(6)1471-84
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Macrocystic Lesions

• Mucinous cystic neoplasms
• Intraductal Papillary Mucinous Neoplasm (IPMN)

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Mucinous cystic neoplasms

• Mucinous cystadenomas cystadenocarcinomas
• Multilocular with complex internal architecture
• May contain internal hemorrhage or debris
• Peripheral Ca predictive of malignancy
• Asymptomatic in 75 cases
• If symptoms, usually due to mass effect
• Mother Lesion
• High potential for malignancy
• Surgical resection yields good prognosis

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• Mucinous cystic neoplasms (mucinous
  cystadenomas) predominantly - involve the body
  and tail of the pancreas
• - they do not
  communicate with the pancreatic duct, they can
  cause partial pancreatic ductal obstruction.

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Intraductal Papillary Mucinous Neoplasm (IPMN)

• IPMNs classified main duct, branch duct
  (side-branch), or mixed IPMNs,
• Main duct IPMN is a morphologically distinct
  entity and cannot be included in the discussion
  of pancreatic cysts.

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• A side-branch IPMN or a mixed IPMN can have the
  morphologic features of a complex pancreatic
  cyst.
• Identification of a septated cyst that
  communicates with the main pancreatic duct is
  highly suggestive of a side-branch or mixed IPMN.
  

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• MR cholangiopancreatography the modality of
  choice for demonstrating
• - the morphologic features of the cyst
  (including septa and mural nodules),
• - the presence of communication between the
  cystic lesion and the pancreatic duct,
• - and evaluating the extent of pancreatic
  ductal dilatation.

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• The occurrence of malignancy is significantly
  higher in main duct and mixed IPMNs than in
  side-branch IPMNs.
• In cases of side-branch IPMN with
• septated pancreatic cysts more than 3 cm in
  diameter
• MDPgt 7mm
• mural nodules
• have a high malignant potential

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Other uncommon tumors (macrocystic lesions)
include non functioning neuroendocrine tumors and
rare congenital malformations such as
lymphangiomas.
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Cysts with a Solid Component

• Unilocular or multilocular
• True cystic tumors or solid pancreatic neoplasms
  with cystic component/degeneration
• Wide DDx
• Mucinous cystic neoplasms
• IPMNs
• Islet cell tumor
• Solid pseudopapillary tumor (SPEN)
• Adenocarcinoma
• Metastasis
• All malignant or have a high malignant potential
• Surgical management

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Cystic neuroendocrine tumor
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Management
Pancreatic cystic lesions Classification
Kloppel et al.WHO Classification.2000
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Management
Pancreatic cystic lesions Predictors of
Malignancy
Verbesy et al. Sur Clin N Am. 2010.
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Management
Cystic lesion in the pancreas
Macrocyst
Microcyst
Cyst with solid component
unilocular
No pancreatitis Nle amylase
Pancreatitis
Mucinous cystadenoma IPMN (branch duct or mixt)
Serous cystadenoma
Malignant neoplasm
Pseudocyst
Consider alternative dx
Dilated MPD(IPMN) symptomatic
asymptomatic
asymptomatic
symptomatic
asymptomatic
symptomatic
Management depends on several factors
Management depends on several factors
Surgery or cyst aspiration
Imaging follow-up
Surgery
Surgery
Surgery
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Management
Pancreatic cystic lesions Natural History and
Prognosis

• Cystic pancreatic neoplasms demonstrate better
  prognosis than adenocarcinoma with 5-year
  survival rates between 20-25.
• Natural history and prognosis of certain cystic
  pancreatic lesions with characteristic imaging
  findings is well-known however, the fate of
  small (lt3cm) lesions is still largely unknown.
• Debate is still going on whether to resect or
  watch these indeterminate lesions.

Verbesy et al. Sur Clin N Am. 2010.
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Follow-up

• No consensus
• 6 month intervals for 1st year
• Annual imaging for 3 years

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TAKE HOME MESSAGES

• Age Gender
• Daughter Lesion SPEN
• Mother Lesion Mucinous cystic
• Grandmother Lesion Serous cystadenoma
• Location
• Head/neck for serous side branch IMPN
• Body/tail for mucinous cystic neoplasm
• Calcification
• Peripheral in mucinous cystic
• Central in serous cystadenoma
• Mural Nodularity (enhancement neoplasm)
• Duct communication (narrow neck) favors IPMN