Cyst fluid analysis can help classify pancreatic cystic lesions when imaging alone is indeterminate, particularly in distinguishing mucinous from non-mucinous pathology. Its role is adjunctive rather than definitive and results should always be interpreted alongside imaging morphology, ductal anatomy, cytology, interval change, and patient-level operative risk. --- ### Practical Interpretation | Marker | Suggests | |---|---| | **High CEA** | Mucinous cyst (IPMN/MCN) | | **Low glucose** | Mucinous cyst | | **High amylase** | Duct communication (IPMN/pseudocyst) | | **KRAS / GNAS** | Mucinous lineage; GNAS supports IPMN | | **VHL** | Supports SCN | | **Positive cytology** | Concerning for HGD/carcinoma | --- ### High-Yield Patterns | Lesion | Typical Pattern | | ------------------------------------------------------------ | ---------------------------------------------- | | **[[Intraductal Papillary Mucinous Neoplasm (IPMN)\|IPMN]]** | High CEA, low glucose, high amylase, KRAS/GNAS | | **[[Mucinous Cystic Neoplasm (MCN)\|MCN]]** | High CEA, low glucose, low amylase | | **[[Serous Cystic Neoplasms (SCNs)\|SCN]]** | Low CEA, normal/high glucose, low amylase, VHL | | **Pseudocyst** | Low CEA, very high amylase | > [!important] > Cyst fluid markers help classify cysts but do not reliably determine malignant potential. --- ### Practical Role Fluid analysis is most useful when: - imaging is indeterminate, - diagnosis would alter surveillance or operative planning, - or cytology/molecular analysis may clarify management. It is less useful when imaging is already classic for SCN, MCN, or advanced IPMN. --- ### Related Pages - [[Pancreatic Cysts]] - [[Intraductal Papillary Mucinous Neoplasm (IPMN)]] - [[Mucinous Cystic Neoplasm (MCN)]] - [[SCN]] - [[Pseudocyst]] - [[EUS]]