2. Introduction
⢠Cystic lesions of the pancreas, typically described on
cross-sectional imaging of the abdomen, refers to
ďźany cystic neoplasms of the pancreas and/or
ďźother cystic lesions, many of which cause âcyst-likeâ
dilatations of the main or side branch pancreatic ducts
3. ⢠The most common non-neoplastic cysts of pancreas are
typically considered to be pancreatic pseudocysts (or
early post-pancreatitis acute fluid collections)
⢠Congenital cysts are rare and include those associated
with genetic diseases such as autosomal dominant
polycystic disease, cystic fibrosis, and von HippelâLindau
(VHL) disease
⢠Most common cystic neoplasm of pancreas is mucinous
cystic neoplasm
4. Epidemiology
⢠Laffan and colleagues in 2008 estimated the incidence of
asymptomatic discovered cysts on abdominal imaging for
unrelated diagnoses at 2.6%
Laffan TA, Horton KM, Klein AP, et al. Prevalence of unsuspected pancreatic cysts on MDCT.
AJR Am J Roentgenol. 2008;191(3):802-807
⢠The incidence of these cystic neoplasms seems to
increase with age, with one autopsy study demonstrating
that up to a quarter of elderly individuals harbor cystic
lesions of the pancreas at their demise
Kimura W, et al. Analysis of small cystic lesions of the pancreas. Int J Pancreatol.
1995;18:197- 206
5. ⢠While the overall risk that an incidental pancreatic cyst is
malignant is very low (about 1 in 10,000)
⢠The risks of surgery are very significant with a 2% to 5%
mortality and 30% to 40% morbidity
6. Classification
⢠Three lesions make up approximately 90% of the cystic
neoplasms seen in the pancreas:
1. serous cystic neoplasms (SCNs),
2. mucinous cystic neoplasms (MCNs), and
3. intraductal papillary mucinous neoplasms (IPMNs)
(Overall, these three common pancreatic cystic neoplasms can be
classified as either âmucinousâ or ânon-mucinous,â a distinction
that has important clinical significance)
7.
8.
9. 1. Serous Cystic Neoplasm
⢠SCNs, previously referred to either as serous
cystadenomas, glycogen-rich adenomas, or microcystic
adenomas, are almost always benign
⢠The majority of SCNs are polycystic or so-called
âmicrocystic adenomasâ
⢠A small number of SCNs (â¤10%) are oligocystic
adenomas and present with one or more dominant cysts
rather than multiple conjoined microcysts
10. ⢠Khashab et al. reported 39% of SCN in the pancreatic
head, 21% in the body, 31% in the tail, and 9% were
considered âextensive.â
⢠Serous cystadenomas are essentially considered benign
tumors without malignant potential.
⢠Serous cystadenocarcinoma has been reported very
rarely (<1%).
11. Pathology
⢠Characterized by a well-circumscribed, soft mass which
includes numerous small cysts filled with clear serous
fluid arranged in a characteristic honeycomb-like pattern
12. ⢠Both microcystic and
oligocystic adenomas are
composed of
-a single layer of simple
cuboidal epithelium with
-rounded nuclei and clear
cytoplasm
-which is glycogen rich and
stains periodic acid-Schiff-
positive
13. Clinical Features
⢠SCNs occur predominately in women in the sixth decade
of life, while men tend to present at a later age
⢠Bassi and colleagues described 100 patients with SCN,
87 of whom were female, with a mean age at presentation
of 52 years, the average age of the 13 male patients was
54 years
Bassi C, et al. Management of 100 consecutive cases of pancreatic serous cystadenoma: wait for
symptoms and see at imaging or vice versa? World J Surg. 2003;27:319-323
14. ⢠In the recent review of 257 cases from the Johns Hopkins
Hospital, 179 patients were female, with a mean age of 61
years
Khashab MA, Shin EJ, Arnateau S, et al. Tumor size and location correlate with behavior of pancreatic
serous cystic neoplasms. Am J Gastroenterol. 2011;106:1521-1526
⢠The majority of patients with SCN are asymptomatic
15. ⢠When symptoms exist,
ďźabdominal pain is the most common presenting symptom
ďźweight loss is seen in 14 to 22% of patients, and
ďźfewer patients (10%) present with a mass or fullness.
ďźSymptoms typically associated with invasive disease,
such as jaundice (6%) or pancreatitis, are uncommon
ďźNausea and vomiting related to compression of the upper
gastrointestinal tract may occur in 7% to 10% of patients
16. Investigation
CT scan
⢠SCNs often have a
characteristic imaging
phenotype Most are well-
demarcated solitary
multicystic masses
composed of innumerable
small cysts
⢠Up to one-third have a
central, calcified starburst
scar
17. ⢠A recent study by Chu and colleagues using pancreas
protocol CT imaging in resected SCNs revealed that only
20% of cases had the âclassic appearanceâ of multilocular
masses with central stellate scars and calcifications
18. `
EUS-FNA
⢠EUS-FNA with cyst fluid cytology and biochemical
analysis. The risk of complications with EUS-FNA is
relatively low
⢠The cystic fluid is serous (clear) and typically has no
mucin content, with a low carcinoembryonic antigen
(CEA) level (< 5 ng/mL) and amylase
⢠If cells are obtained, which is rare, they are cuboidal and
have a clear cytoplasm
19. Treatment
⢠Observation of patients with SCN may be appropriate in
asymptomatic patients
⢠Resection is indicated if
-symptomatic
-size >4cm
-diagnostic uncertainity
20. ⢠Enucleation of SCNs has been shown to be technically
feasible, although it can be challenging and is associated
with a significant risk of pancreatic fistula
⢠Lesions in the head of the pancreas that are not
amenable to enucleation are best treated with pylorus-
preserving pancreaticoduodenectomy
21. ⢠A central pancreatectomy, with remnant pancreatic
reconstruction being performed via pancreaticogastrostomy
or Roux-en-Y pancreaticojejunostomy (PJ), may be
considered in select patients with lesions of the pancreatic
neck
⢠Distal pancreatectomy with splenic preservation may also be
considered, particularly for small lesions in the tail
22. Follow up
⢠Patients with pathologically proven, completely resected
SCNs do not require serial imaging in follow-up
⢠Recommendations for appropriate monitoring of
unresected SCNs vary, but serial imaging with either CT
or MRI every 6 months for 2 years and then annually or
every other year thereafter seems reasonable
23. 2. Mucinous cystic neoplasm
⢠Mucinous cystic neoplasms (MCNs) encompass a
spectrum ranging from benign but potentially malignant to
carcinoma with a very aggressive behavior
⢠MCNs are commonly seen in perimenopausal women,
and about two-thirds are located in the body or tail of the
pancreas
⢠Frequently seen in young women, the mean age at
presentation is in the fifth decade, men are rarely affected
24. ⢠MCNs exhibit characteristics of an adenoma-carcinoma
sequence
⢠Dependent on the degree of atypia, they are classified as
mucinous cystadenomas, mucinous cystic tumors
(borderline lesions), in situ lesions (high-grade dysplasia),
or invasive cystadenocarcinomas (mucinous
cystadenocarcinomas)
25. ⢠tall columnar mucin-producing
epithelium
⢠accompanied by a subendothelial
ovarian-type stroma that appears as
a dense layer of spindle cells with
sparse cytoplasm and uniform,
elongated nuclei
⢠This stroma regularly expresses
progesterone receptors, and less
frequently estrogen receptors, and
over 60% of these stroma stain for
human chorionic gonadotropin
26. ⢠Both the WHO and the Armed Forces Institute of
Pathology (AFIP) have defined the presence of this
ovarian-like stroma as a requirement for the diagnosis of
an MCN
⢠In addition, MCNs typically do not communicate with the
pancreatic ductal system, and this serves as another
distinction between IPMNs
27. Clinical Features
⢠Abdominal pain or discomfort is the most common
presenting symptom, occurring in over 70% of patients
⢠A history of acute pancreatitis may also be elicited in 9%
to 13% of patients, although less commonly than in
patients with IPMN
⢠early satiety, and
⢠weight loss
28. Investigation
Imaging
⢠MCNs contain large septated
cysts with thick irregular walls
that may be well visualized on
CT, MRI, or ultrasound evaluation
⢠In a minority of cases, the wall of
the MCN may contain
calcifications, a characteristic
associated with a higher
likelihood of malignancy
29. ⢠MCNs may also present as large
unilocular cysts that may appear
similar on cross-sectional imaging to
long-standing pseudocysts
⢠Two distinguishing characteristics in
this scenario that suggest the
diagnosis of MCN are the lack of
surrounding inflammatory changes
beyond the wall of the neoplasm in
MCNs and the absence of pancreatitis
30. ⢠Analysis of cyst fluid aspirated from MCNs typically show
ďźmucin content,
ďźelevated levels of CEA and
ďźlow amylase concentrations (as MCNs do not typically
communicate with the pancreatic ductal system)
⢠The utility of detailed DNA analysis of pancreatic cyst fluid
to diagnose mucinous and malignant cysts has been
evaluated in the PANDA study
31. ⢠The study concluded that cyst fluid K-ras mutation was
helpful in the diagnosis of mucinous cysts with a 96%
specificity
⢠The criteria of high amplitude K-ras mutation followed by
allelic loss showed maximum specificity (96%) for
malignancy
32. ⢠In reviewing MCNs, the authors approached 90%
sensitivity and 97% specificity with the combination of
certain molecular markers
ďźincluding the absence of CTNNB1I and GNAS mutations,
ďźloss of heterozygosity on chromosome 3, and
ďźaneuploidy in chromosome 1q and 22q and
⢠the following clinical markers: age <75 years old and the
absence of all three of the following features:
ďźmale sex, communication with the main pancreatic ductal
system, and multiple cysts
Springer S, Wang Y, Dal Molin C, et al. A combination of molecular markers and clinical features improve
33. ⢠Biopsy of MCN should not be utilized to determine the
presence of carcinoma, because the presence of invasion
within a lesion may be patchy or discontiguous and a
negative biopsy result may be obtained erroneously
based on sampling error
34. Treatment
⢠Resection is the treatment of choice for most mucin-
producing cystic tumors
ďźsymptomatic neoplasms,
ďźlesions greater than 3 cm, or
ďźthose containing nodules or papillae should undergo
resection
⢠Malignancy cannot be ruled out without removal and
extensive sampling of the entire tumor
⢠Malignancy has been reported in 6% to 36% of MCNs.
Current thinking is that all of these tumors will eventually
evolve into cancer if left untreated
35. ⢠Because most MCNs are located in the body and tail of
the pancreas, distal pancreatectomy is the most
common treatment
⢠For small lesions, it may be appropriate to preserve the
spleen, but splenectomy ensures removal of the lymph
node basin that can potentially be involved
⢠It is very important not to rupture the cyst during
resection, and the tumor should be removed intact, not
36. ⢠Adjuvant chemotherapy or chemoradiation therapy for
mucinous cystadenocarcinoma has been poorly
investigated and has no proven benefit
37. Follow up and prognosis
⢠Non-invasive MCNs require no surveillance after
resection
⢠For MCNs with an associated invasive carcinoma,
prognosis depends on the extent of the invasive
component, tumor stage, and resectability
⢠The 2-year survival rate and 5-year survival rate of
patients with resected MCN with an associated invasive
carcinoma are about 67% and 50%, respectively
38. 3. Intraductal papillary mucinous neoplasms(IPMN)
⢠IPMNs are mucin-producing epithelial tumors arising from
the pancreatic ductal system that cause dilation of this
system
⢠Usually occur within the head of the pancreas and arise
within the pancreatic ducts
⢠In 1996, the WHO first formally recognized IPMN as a
distinct entity; establishing criteria for the pathological
diagnosis of these lesions
39. ⢠Both genders are affected by IPMNs, with a moderate
male predominance in some series
⢠Patients with IPMN tend to be older, with a mean age of
65 years, as compared with those having MCN, who are
predominantly perimenopausal
40. Classification
⢠The proliferation of mucinous cells may involve the
ďźmain pancreatic duct (âmain duct type,â MD-IPMN), or
ďźbe confined to the branch ducts (âbranch duct type,â BD-
IPMN), or
ďźshow a pattern spanning both areas in a âmixed-typeâ
42. Pathology-Microscopic
⢠Characteristic features include a
ďźtall columnar epithelium with
ďźthe ductal epithelium forms a
papillary projection into the duct,
and
ďźmucin production causes
intraluminal cystic dilation of the
pancreatic ducts
43. Clinical Features
⢠Main duct type and combined main duct and branch duct
type lesions (mixed-type) are more likely to present with
symptoms
⢠BD-IPMNs are more frequently detected as asymptomatic
cystic neoplasms on cross-sectional imaging
⢠Pancreatitis is seen more commonly in MD-IPMN
44. ⢠Malignant IPMNs are more likely to present with
symptoms typically attributed to ductal adenocarcinoma,
such as obstructive jaundice and weight loss
⢠Some patients (5â10%) have steatorrhea, diabetes, and
weight loss secondary to pancreatic insufficiency
45. Investigation
⢠At ERCP, mucin can be seen
extruding from the ampulla of
Vater, a so-called fish-eye
lesion that is virtually
diagnostic of IPMN
46. ⢠Imaging studies demonstrate
diffuse dilation of the
pancreatic duct, and the
pancreatic parenchyma is
often atrophic due to chronic
duct obstruction.
⢠However, classic features of
chronic pancreatitis, such as
calcification and a beaded
appearance of the duct, are
not present
47.
48. ⢠Branch Duct IPMN:
resection
ďźsymptomatic
ďźsize>3cm
ďźpositive cytology
ďźmural nodule
ďźrapid growth
ďźmain duct dilation
ďźyoung and healthy
(age<55 years)
⢠Main Duct IPMN: resection
ďźresect using intraoperative
pancreatoscopy and
ďźcareful inspection of
remenant pancreas for
synchronous pancreatic
neoplasm
49.
50.
51. References
⢠Schwartzâs Principles Of Surgery 11th edition
⢠Maingotâs Abdominal Operation 13th edition
⢠Sabiston Textbook Of Surgery 21st edition
⢠Bailey & Love 27th edition
⢠Pubmed