Fine-Needle Aspiration-Based Grading of Pancreatic Neuroendocrine Neoplasms Using Ki-67: Is Accurate WHO Grading Possible on Cytologic Material?

摘要: Introduction The World Health Organization (WHO) has provided grading guidelines for pancreatic neuroendocrine neoplasms (PanNENs) based on mitotic count and Ki-67 proliferation index. Driven by the desire to provide earlier tumor clinical management decisions, some groups have proposed PanNENs at time of fine-needle aspiration (FNA) using rates. Although a rate can be performed FNA cell blocks, there are potential sampling limitations with this technique that may affect reliability result. Materials Methods Forty-nine blocks corresponding resection material were evaluated immunohistochemistry expression Ki-67. was calculated counts >500 cells in highest-staining areas. scores from correlated specimens. Results rates overall did not correlate well specimen. A linear regression analysis correlation between %Ki-67 showed slope 3.2 an R2 = 0.58. average difference 5.9%. Thirty-nine percent (19 49 cases) discordant block Almost all (18 19) cases demonstrated lower FNA-based grade than grade. Conclusions frequently led under-grading tumor. This finding is consistent concerns accurate because limited