Optimizing the multimodal approach to pancreatic cyst fluid diagnosis: developing a volume-based triage protocol

Area of Science:

• Gastroenterology
• Oncology
• Pathology

Background:

• Pancreatic cysts require accurate diagnosis for appropriate management.
• Current diagnostic methods for pancreatic cyst fluid have limitations.
• Optimizing the use of available specimen components is crucial for diagnostic yield.

Purpose of the Study:

• To develop a triage algorithm for pancreatic cyst fluid analysis.
• To optimize diagnostic yield using cytology, carcinoembryonic antigen (CEA), and v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) testing.
• To assess the suitability of cell block supernatant for CEA and KRAS testing.

Main Methods:

• A volume-dependent protocol was used to triage 54 pancreatic cysts.
• Fluid (neat and supernatant) and cell block specimens were analyzed.
• Cytology, CEA, and KRAS testing were performed, with final diagnosis based on histology or clinicopathologic interpretation.

Main Results:

• The protocol enabled testing on 92.6% of cyst fluids.
• High interpretive concordance was observed for CEA (100%) and KRAS (87.5%) testing.
• Elevated CEA was the most sensitive marker for mucinous lesions (62.5%), while KRAS mutations were found in 8% of mucinous cysts when other tests were inconclusive.

Conclusions:

• A volume-based protocol effectively optimizes diagnostic yield from pancreatic cyst fluids.
• KRAS mutation testing, alongside cytology and CEA, improves diagnostic accuracy.
• Supernatant is a viable alternative to neat fluid and cell block material for CEA and KRAS testing.