Nature and management of pancreatic mucinous cystic neoplasm (MCN): A systematic review of the literature.
BACKGROUND
The current management of pancreatic mucinous cystic neoplasms (MCN) is defined by the consensus European, International Association of Pancreatology and American College of Gastroenterology guidelines. However, the criterion for surgical resection remains uncertain and differs between these guidelines. Therefore through this systematic review of the existing literature we aimed to better define the natural history and prognosis of these lesions, in order to clarify recommendations for future management.


METHODS
A systematic literature search was performed (PubMed, EMBASE, Cochrane Library) for studies published in the English language between 1970 and 2015.


RESULTS
MCNs occur almost exclusively in women (female:male 20:1) and are mainly located in the pancreatic body or tail (93-95%). They are usually found incidentally at the age of 40-60 years. Cross-sectional imaging and endoscopic ultrasound are the most frequently used diagnostic tools, but often it is impossible to differentiate MCNs from branch duct intraductal papillary mucinous neoplasms (BD-IPMN) or oligocystic serous adenomas pre-operatively. In resected MCNs, 0-34% are malignant, but in those less than 4 cm only 0.03% were associated with invasive adenocarcinoma. No surgically resected benign MCNs were associated with a synchronous lesion or recurrence; therefore further follow-up is not required after resection. Five-year survival after surgical resection of a malignant MCN is approximately 60%.


CONCLUSIONS
Compared to other pancreatic tumors, MCNs have a low aggressive behavior, with exceptionally low rates of malignant transformation when less than 4 cm in size, are asymptomatic and lack worrisome features on pre-operative imaging. This differs significantly from the natural history of small BD-IPMNs, supporting the need to differentiate mucinous cyst subtypes pre-operatively, where possible. The findings support the recommendations from the recent European Consensus Guidelines, for the more conservative management of MCNs.
Karolinska Institutet, Stockholm, Sweden.
Linda N
LN
Nilsson
Institute for Liver and Digestive Health, University College London, UK.
Margaret G
MG
Keane
Southampton University Hospital, UK.
Awad
A
Shamali
Miguel Servet University Hospital, Zaragoza, Spain.
Judith
J
Millastre Bocos
Radboud University Medical Center Nijmegen, Netherlands.
Monica
M
Marijinissen van Zanten
Tampere University Hospital, Tampere, Finland.
Anne
A
Antila
Ciudad Real University Hospital, Spain.
Cristina
C
Verdejo Gil
Karolinska Institutet, Stockholm, Sweden.
Marco
M
Del Chiaro
Tampere University Hospital, Tampere, Finland. Electronic address: johanna.laukkarinen@fimnet.fi.
Johanna
J
Laukkarinen
D006801:Humans; D018297:Neoplasms, Cystic, Mucinous, and Serous / Q000453:epidemiology / Q000473:pathology / Q000628:therapy*; D010181:Pancreatic Cyst / Q000473:pathology / Q000628:therapy; D010190:Pancreatic Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000628:therapy*
MCN; Mucinous cystic neoplasm; Pancreatic cystic neoplasm; Pancreatic cystic tumor