Pathologic interpretation of endoscopic ultrasound–guided fine needle aspiration cytology/biopsy for pancreatic lesions

Abstract

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) cytology/biopsy is currently performed at many institutions and has become a routine procedure for pathologic diagnosis of pancreatic lesions. Although endoscopic ultrasound scanning began in the early 1980s [1], it has gained widespread popularity since the introduction of fine needle aspiration cytology/biopsy devices, which allow guided biopsies of target lesions visualized by endoscopic ultrasound [2]. Before the era of EUS-FNA, it was difficult to target pancreatic lesions due to limited accessibility by percutaneous needle biopsies. Hence, pathologists could rarely encounter cytology and/or biopsy material from pancreatic lesions. With the increasing popularity of EUS-FNA procedures, interpretation of EUS-FNA cytology/biopsy material has become an almost inevitable part of routine practice for pathologic diagnosis of various pancreatic lesions. A main concern of pancreatic EUS-FNA specimen interpretation is the limited amount of aspirated material. Compared to aspirated material from superficial organs, such as the thyroid, breast, or uterine cervix, EUS-FNA from pancreatic lesions provides aspirates with relatively limited cellularity that may seem inadequate to less experienced pathologists. However, EUS-FNA inevitably results in lower cellularity compared to aspirates from other superficial organs. To make an appropriate diagnosis, pathologists should consider the clinical impression, especially radiologic and/or EUS findings; otherwise, many EUS-FNA specimens may be interpreted as "inadequate specimen". It is occasionally necessary to deem the sample "inadequate", "atypical", or of "uncertain malignant potential", which are diagnostically less useful to clinicians, but necessary. The use of these indeterminate categories will be reduced with expertise and correlation of cytologic

A prospective randomized noninferiority trial comparing conventional smears and SurePathTM liquid-based cytology in endoscopic ultrasound-guided sampling of esophageal, gastric, and duodenal lesions

“…Consistent with previous studies, [11,23,24] our study found that the number of inadequate specimens was lower in LBC compared to CSs, and the proportion of clean backgrounds was significantly higher in LBC. EUS-FNA of the upper GI tract showed relatively limited cellularity compared to superficial organs such as the uterine cervix and thyroid, [7] and sufficient cellularity, as well as the background, is one of the important requirements for pathologic diagnosis. In our study, the rate of moderate to very high cellularity was 73.3% for LBC, which was slightly higher than 68.3% for CSs but not statistically significant ( P = .549).…”

“…In CSs, material obtained by aspiration is smeared on glass slides and placed in a 95% alcohol fixative for additional staining. [7] LBC is not a direct smear of a specimen on a slide, but a process in which the specimen is suspended in a preservative solution and then uniformly mixed by vortexing or rotation to remove unnecessary cell debris, mucus, and blood cells. After going through this process, it is made into a relatively homogeneous single-cell sample.…”

Comparison of Endoscopic Ultrasound-Guided Fine Needle Aspiration with 19-Gauge and 22-Gauge Needles for Solid Pancreatic Lesions

“…5 , 6 Additionally, diseases such as autoimmune pancreatitis, solid pseudopapillary tumors, and neuroendocrine tumors, may be difficult to diagnose without a large amount of tissues for immunohistochemical analysis. 7 , 8 …”