A review of pancreatic cyst fluid analysis in the differential diagnosis of pancreatic cyst lesions

Abstract

Diagnosis and management of pancreatic cyst lesions is challenging as there is currently no investigation that offers both high diagnostic sensitivity and high specificity for the identification of potentially malignant lesions. Accurate classification of these lesions is vital in order to avoid unnecessary treatment of benign lesions and missed opportunities for early treatment of lesions that are malignant/pre-malignant. Pancreatic cyst fluid analysis has an important role in diagnosis, although all currently available investigations based on fluid analysis have significant limitations. Cytological analysis can reveal features that are specific for a certain class of cyst, but offers limited sensitivity in detecting malignant/premalignant cysts. Measurement of tumour markers, particularly carcinoembryonic antigen can also be informative. Concentrations of cyst fluid carcinoembryonic antigen tend to be higher in malignant/pre-malignant cysts, although there is a wide overlap between the various classes of cyst. A number of studies have suggested that diagnostic carcinoembryonic antigen cut-offs can be chosen that provide a high degree of specificity but limited sensitivity. Studies of the analytical validity of tumour marker assays in pancreatic cyst fluid analysis have highlighted discrepancies in some fluid specimens, which require further investigation. DNA analysis also has a role. In particular, K-Ras-2 mutational analysis appears to provide high specificity for detection of malignant/pre-malignant lesions. A number of diagnostic algorithms have been published, integrating use of available investigations in order to achieve the optimum discrimination of benign and potentially malignant cysts. Research into new biochemical markers and optimal use of available pancreatic cyst fluid analyses is ongoing.

Prospective validation of microRNA signatures for detecting pancreatic malignant transformation in endoscopic-ultrasound guided fine-needle aspiration biopsies

“…Computer tomography (CT) and magnetic resonance imaging (MRI) are unable to accurately distinguish between benign and malignant pancreatic cystic lesions [4] and therefore the majority of patients undergo an endoscopic ultrasound scan (EUS) and fine needle aspiration (FNA) for cytology and cystic fluid analysis. EUS can differentiate between benign, pre-malignant and malignant lesions with an accuracy ranging from 40 to 93% [5][6][7].…”

Light scattering spectroscopy identifies the malignant potential of pancreatic cysts during endoscopy

“…Because some pancreatic cysts are precancerous, and because pancreatic cancer is such a deadly condition, diagnosing the type of pancreatic cyst lesion accurately is a high stakes challenge. Despite the recent improvements in CT and MRI methodologies, these imaging approaches are unable to distinguish cancerous, premalignant and benign cysts reliably, in part due to a lack of sensitivity to cellular structure and biochemical properties, with wide variations in the reported accuracy ranging from 20% to 80% 37 . EUS is still the most sensitive technique currently available for the detection of small (<2–3 cm) pancreatic cysts 38,39 , however, the accuracy of EUS for distinguishing mucinous from non-mucinous cysts is only 51% 6 .…”

Intraductal papillary mucinous neoplasms of the pancreas: radiological predictors of malignant transformation and the introduction of bile duct dilation to current guidelines

“…This study hypothesized that the increase of viscosity is the result of higher glycoprotein or mucin expression. Further studies analysing pancreatic fluid cysts have shown that many transmembrane proteins and mucinous columnar cells are sloughed with higher grades of dysplasia, which may also impact viscosity, 20 a fact which is currently under evaluation for predicting malignant potential in cystic pancreatic neoplasms using diffusionweighted imaging. 21 Therefore, inference may be drawn that CBD dilation occurs owing to increased viscosity of the pancreatic fluid and the change of the fluid dynamics.…”