PCL may be benign,
with malignant potential or overt malignant masses.
Imaging aspects are of rising importance because they represent a non-invasive,
relatively accurate method of establishing a diagnosis.
General considerations regarding PCL:
- Increasingly discovered on cross-sectional imaging [1,2]
- Accurate assessment is important for management [1-4]
- Pancreatic cystic neoplasms represent a histological heterogeneous collection of neoplasms,
showing a spectrum of diagnoses,
from completely benign to potentially malignant,
carcinoma in situ,
frankly invasive and malignant [2,3]
- Studies using MRI imaging established an overall prevalence of PCL of 15%,
in comparison with studies using CT imaging,
which report a prevalence of 3% [1-4]
- The prevalence of pancreatic cystic lesions varies upon different age groups,
between 0.5% and 37% [1-4]
Classification of PCL:
Pancreatic cystic lesions are divided into benign lesions,
potentially malignant lesions and malignant lesions.
The cysts can be divided into non-neoplastic and neoplastic cysts.
- Non neoplastic cysts – benign [5]
• Pseudocyst
• Simple/congenital cyst
• Retention cyst
• Hydatid cyst
- Neoplastic cysts – potentially malignant or overt malignant lesions [5]
• Non-mucinous cystic neoplastic lesions
Serous cystic neoplasms
Cystic endocrine tumor
Solid pseudopapillary tumor
Acinar cell cystadenocarcinoma
• Mucinous cystic lesions
Mucionous cystadenoma/carcinoma
Intraductal Papillary Mucinous Neoplasm (IPMN)
- Other neoplastic lesions [5] - Ductal adenocarcinoma with cystic degeneration
Risk factors for developing malignant PCLs [6-12]:
- Cigarette smoking - doubles the risk of pancreatic cancer;
- Obesity – BMI ≥ 30;
- Diet – consumption of >60 g liquor per day; no association with beer and wine consumption reported;
- Diabetes mellitus - almost duplicates the risk;
- Chronic pancreatitis- 4% of patients develop pancreatic cancer;
- Hereditary- 5-10%,
e.g.
MEN II syndrome.
Serous cystadenoma [13]:
Ø Benign tumors originating from acinary cells;
Ø 50% of all cystic pancreatic neoplasms;
Ø Can be associated with von Hippel Lindau syndrome (vHL);
Ø Mean age: 65 years old; M/F ratio: 1:4;
Ø Corporeal region – most frequent site;
Ø Clinical presentation: weight loss,
jaundice,
abdominal pain.
Mucinous cystadenoma [14,15]:
Ø uni-/multilocular cystic mass,
thick wall,
containing mucin;
Ø no communication with the pancreatic ductal system;
Ø body or tail of the pancreas in 95-98% of the cases;
Ø usually asymptomatic.
Mucinous cystadenocarcinoma: malignant variant of mucinous cystadenoma [14,15]
Intraductal Papillary Mucinous Neoplasm (IPMN) [16,17]:
Ø Cystic mucus producing mass associating Wirsung dilation;
Ø Excessive mucus production causing Wirsung obstruction;
Ø Localization: from head to tail;
Ø Male more frequent than female;
Ø Site and extension:
Main Duct IPMN (MD-IPMN)
Branch Duct IPMN (BD-IPMN)
Mixed forms
Cystic pancreatic endocrine neoplasm [18,19]:
Ø About 8% of resected cystic tumors;
Ø 13-17% of pancreatic neuroendocrine tumors;
Ø generally assumed that cystic pancreatic neuroendocrine tumors are the result of tumor necrosis within solid pancreatic neuroendocrine tumors - often a component of a large tumor with cystic degeneration or necrosis;
Ø more commonly located in the neck,
body or tail of the pancreas than in the head compared with solid counterpart;
Ø Variable size;
Ø usually the cysts do not communicate with the pancreatic ducts.
Solid pseudopapillary neoplasm [20]:
Ø Also known as Hamoudi tumor;
Ø Rare tumor (1-2% of exocrine pancreatic tumors);
Ø Young Caucasian female;
Ø Mean age diagnosis 20-30 years old;
Ø Clinical asymptomatic,
or vague abdominal pain;
Ø Tumor consisting in various amounts of necrosis,
hemorrhage,
and cystic change;
Ø Usually large at time of diagnosis (over 8 cm).
Cystic degeneration of pancreatic ductal adenocarcinoma (PDAC) [20,21]:
Ø 80-95% of non-endocrine pancreatic tumors;
Ø Mean age: 55 year old; male to female ratio: 2/1;
Ø 65% of the patients have locally advanced or metastatic PDAC at the time of diagnosis;
Ø 4% of patients have a localized tumor;
Ø head of the pancreas (50-60%),
body (26%),
tail (12%);
Ø 21% of cases present limph nodes invasion;
Ø Metastases: 30-36% liver,
lung,
pleura,
bone;
Ø Clinical presentation: weight loss, fatigue,
anorexia,
jaundice (75%),
abdominal pain.