Transcript Imaging of Pancreatic Cystic Lesions

Dr Zaghouani. H, Pr Kraiem Ch
Service d’imagerie Farhat Hached
5th ARC of PAARS& 6th annuel Meeting of PAIRS
25-28 April Hammamet
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.
Clinical Presentation
• A large number of pancreatic cysts are incidentally detected
during imaging work-up for an unrelated medical problem.
Epidemiologic characteristics
Brugge WR Eng J Med 2004
Morphologic Classification of Cystic Pancreatic Lesions
Radiographics 2005 Nov-Dec;25(6):1471-84
Unilocular Cysts
•
•
•
•
•
Pseudocyst
IPMN occasionally
Unilocular serous cystadenoma
Lymphoepithelial cyst
Multiple:
– Von Hippel-Lindau, Polycystic kidney disease
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
Traumatic pseudocyst
Unilocular serous cystadenoma
• When there is a unilocular cyst with a lobulated contour
located in the head of the pancreas: unilocular macrocystic
serous cystadenoma.
Side-branch IPMN manifesting as a
unilocular cyst
Multiple unilocular cysts in a patient with
von Hippel–Lindau disease
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 (>6)
– Range: few mm – 2 cm
– External lobulations
– Enhancing septa, walls
• 30% demonstrate fibrous central
scar +/- stellate calcifcation
• Other variants of these tumors
(macrocystic + oligocystic)
Serous cystadenoma: MRI
 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-Dec;25(6):1471-84
Macrocystic Lesions
• Mucinous cystic neoplasms
• Intraductal Papillary Mucinous Neoplasm
(IPMN)
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
• 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.
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.
• 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.
• 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.
• 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
- MDP> 7mm
- mural nodules
have a high malignant potential
Other uncommon tumors (macrocystic lesions) include non
functioning neuroendocrine tumors and rare congenital
malformations such as lymphangiomas.
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
Cystic neuroendocrine tumor
Management
Pancreatic cystic lesions: Classification
Kloppel et al.WHO Classification.2000
Management
Pancreatic cystic lesions: Predictors of Malignancy
Verbesy et al. Sur Clin N Am. 2010.
Management
Cystic lesion in the pancreas
Microcyst
unilocular
Macrocyst
No pancreatitis
Nle amylase
Pancreatitis
Pseudocyst
Cyst with solid component
Consider alternative dx
asymptomatic
Management
depends on several
factors
symptomatic
Surgery or
cyst aspiration
Serous cystadenoma
asymptomatic
Imaging follow-up
Malignant neoplasm
symptomatic
Surgery
Mucinous cystadenoma
IPMN (branch duct or mixt)
Dilated MPD(IPMN)
symptomatic
Surgery
Surgery
asymptomatic
Management
depends on
several factors
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
(<3cm) 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.
Follow-up
• No consensus
• 6 month intervals for 1st year
• Annual imaging for 3 years
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