Ahn B, Jung JK, Jung H, Ryu YM, Kim YW, Song TJ, Park DH, Hwang DW, Cho H, Kim SY, Hong SM. Double Ki-67 and synaptophysin labeling in pancreatic neuroendocrine tumor biopsies.
Pancreatology 2022;
22:427-434. [PMID:
35292233 DOI:
10.1016/j.pan.2022.03.005]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 02/21/2022] [Accepted: 03/06/2022] [Indexed: 12/11/2022]
Abstract
BACKGROUND
Pancreatic neuroendocrine tumors (PanNETs) are frequently detected on endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) specimens. The conventional methods for evaluating the Ki-67 labeling index (Ki67LI) in EUS-FNAB specimens are laborious, and their results are difficult to interpret. More practical and easy methods for evaluating the Ki67LI in PanNETs from EUS-FNAB specimens is increasing in need.
METHODS
We used double Ki-67 and synaptophysin (double Ki-Syn) antibody cocktail; Ki67LI, total Ki-67 positive cells, and total tumor cells were counted and compared with those detected on conventional single Ki-67 immunostaining (single Ki-67) of 96 PanNETs [Grade 1 (G1), 68 cases (71%); G2, 26 (27%); G3, 2 (2%)] from EUS-FNAB specimens.
RESULTS
The tumor grading between double Ki-Syn and single Ki-67 immunolabeling was highly concordant (correlation, 0.95; Fisher's exact test, P < 0.001). Seven EUS-FNAB specimens (7%) had discrepant results, of which 2 were removed through surgical resection and showed the same tumor grade as that detected on double Ki-Syn immunolabeling. Fifty-four specimens (56%) had higher Ki-67 positive tumor cell counts on single Ki-67 immunolabeling. Sixty-two specimens (65%) had higher total tumor cell counts on double Ki-Syn immunolabeling. The number of specimens with less than 500 total counted tumor cells were significantly reduced when double Ki-Syn immunolabeling was applied [P = 0.046; single Ki-67, 17 specimens (18%); double Ki-Syn, 9 specimens (9%)].
CONCLUSION
Double Ki-Syn immunolabeling enables the accurate counting of the number of proliferating tumor cells without including inflammatory and contaminant epithelial cells compared with single Ki-67 immunolabeling in PanNETs from EUS-FNAB specimens.
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