Processing of Fine-Needle Aspiration Specimens from Pancreatic Lesions

It is important to adequately process and triage the specimen obtained from fine-needle aspirations (FNAs) of pancreatic lesions. Many echo endoscopists rely on rapid on-site evaluation (ROSE) for adequacy of FNA from solid pancreatic lesions. The role of ROSE in FNA of pancreatic lesions is discussed, as is the triage of material for making smears and cell block preparation. Different techniques of cell block preparation are briefly mentioned. Pancreatic cystic fluid obtained from pancreatic cysts is triaged differently as compared to specimens obtained from solid pancreatic lesions. An algorithmic approach to the processing of pancreatic cystic fluid for molecular and biochemical assays and cytology is discussed. Proper specimen handling is crucial to the accurate interpretation of pancreatic FNA specimens. The methods used to process a sample depend on whether the aspirated sample is solid or cystic and the type of device used for sampling. ROSE has been shown to reduce the number of inadequate specimens and to improve specimen preparation. The details of the various cytological preparation methods available are described in numerous texts. Here we focus on providing a broad overview of specimen collection and processing as it relates to pancreatic FNA, with guidance to the reader based on published and personal experiences.