Gastroenterology· Topic 5.6 Pancreatic disease· 5.6.14

Pancreatic cystic neoplasms

Pancreatic cystic neoplasms are epithelial-lined cysts of the pancreas, divided into mucin-producing lesions with malignant potential (intraductal papillary mucinous neoplasm and mucinous cystic neoplasm) and non-mucin-producing serous cystadenomas with essentially none. Most are found incidentally; imaging morphology and high-risk features (symptoms, size 3 cm or more, main duct dilation, solid component) decide between no follow-up, MRI surveillance, endoscopic ultrasound with cyst fluid analysis, and surgical resection, which is the only treatment.

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What this article covers

  • Overview

    Definition: pancreatic cystic neoplasms are true, epithelium-lined cystic tumors of the pancreas, distinct from the inflammatory pancreatic pseudocyst, whose wall is granulation tissue without an epithelial lining.

  • Epidemiology

    Common incidental finding: cysts are found in 15% of patients undergoing abdominal imaging and are most common in older adults (over 70 years); detection is rising with use and quality of cross-sectional imaging.

  • Risk factors

    Main pancreatic duct involvement: the strongest predictor of malignancy; main-duct IPMN has a malignant transformation rate as high as 65%.

  • Pathophysiology

    Mucinous neoplasia of the ductal system: IPMN is an intraductal mucin-producing neoplasm arising from the main pancreatic duct or, more often, a side branch; main-duct disease dilates the main…

  • Clinical features

    Usually asymptomatic and incidental: most cysts are found on imaging performed for an unrelated reason, such as abdominal pain from another cause.

  • Differential diagnosis

    Pancreatic ductal adenocarcinoma with cystic features: a firm mass with cystic change, jaundice, weight loss, and new-onset diabetes; a solid component on imaging should be treated as cancer until proven otherwise (pancreatic cancer).

  • Diagnosis

    How the diagnosis is established: no single criteria set or definitive test exists; the cyst is classified as mucinous or non-mucinous by cross-sectional imaging morphology, then risk-stratified by…

  • Management

    First, decide whether the cyst is non-mucinous and benign: classic serous cystadenoma needs no further evaluation or intervention unless symptomatic, and a confirmed pseudocyst is drained only if symptomatic or infected, regardless of size.

  • Complications

    Invasive pancreatic adenocarcinoma: the most serious outcome, most likely from main-duct IPMN (up to 65%) and MCN; once invasive, prognosis is that of pancreatic cancer.

  • Prognosis

    Most cysts never become malignant: branch-duct IPMN has a low rate of malignant transformation, and serous cystadenoma has none.

  • Prevention

    Resect before invasion: the only preventive measure for cyst-derived cancer is resection of cysts with high-risk features (size of 3 cm or more, dilated main duct, solid component, jaundice, or…

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