Grading by the Ki-67 Labeling Index of Endoscopic Ultrasound–Guided Fine Needle Aspiration Biopsy Specimens of Pancreatic Neuroendocrine Tumors Can Be Underestimated. Issue 10 (November 2018)

• Record Type: Journal Article
• Authors: Hwang, Hee Sang; Kim, YunJae; An, Soyeon; Kim, Sung Joo; Kim, Joo Young; Kim, Sang-Yeob; Hwang, Dae Wook; Park, Do Hyun; Lee, Sang Soo; Kim, Song Cheol; Seo, Dong-Wan; Hong, Seung-Mo
• Is Part Of: Pancreas. Volume 47:Issue 10(2018)
• Publication Date: 2018-11
• Subjects: pancreas -- neuroendocrine tumor -- Grading -- MIB1 -- immunohistochemistry; Pancreas -- Diseases -- Periodicals; Pancreas -- Periodicals; Neuroendocrine tumors -- Periodicals; 616.37005
• DOI: 10.1097/MPA.0000000000001157
• Languages: English
• ISSNs: 0885-3177

Abstract

Abstract : Objectives: There is an increasing need for grading with small endoscopic ultrasound–guided fine needle aspiration biopsy (EUS-FNAB) specimens for the proper diagnosis and therapy selection of patients with unresectable pancreatic neuroendocrine tumors (PanNET). However, our understanding of EUS-FNAB specimen grading is limited compared with surgically resected specimens. Methods: We retrospectively determined Ki-67 labeling index (LI) of 33 matched EUS-FNAB and surgically resected PanNETs with digital image analyzer. Pairwise grades between the matched biopsy and surgically resected PanNET specimens were compared. Results: The mean Ki-67 LI was higher in surgically resected PanNET specimens (5.5%) than in biopsy specimens (3.2%; P = 0.022). There was moderate agreement between the Ki-67 LI grades when individually evaluated matched biopsy and resected specimen pairs were compared (κ value = 0.62; P < 0.0001). However, discordance was noted in 6 cases (18%), and all of them were either grade 2 or 3 in resected PanNETs. Conclusions: Although Ki-67 LI grading of EUS-FNAB specimens may be concordant with that of matched surgically resected specimens in a large proportion of the PanNET cases, Ki-67 LI grading of EUS-FNAB specimens should be carefully applied in clinical practice because of the possibility of grading underestimation with grade 2 to 3 PanNET cases. Abstract : Supplemental digital content is available in the text.