Endoscopy 2020; 52(S 01): S161-S162
DOI: 10.1055/s-0040-1704499
ESGE Days 2020 ePoster Podium presentations
Friday, April 24, 2020 09:30 – 10:00 Neuroendocrine tumors ePoster Podium 3
© Georg Thieme Verlag KG Stuttgart · New York

KI-67-INDEXING OF EUS-GUIDED FINE NEEDLE BIOPSY SPECIMENS FOR THE PREOPERATIVE GRADING OF PANCREATIC NEUROENDOCRINE TUMORS

F Bergstedt
1   Göteborg, Sweden
,
A Appelstrand
2   Sahlgrenska University Hospital, Department of Clinical Pathology and Genetics, Gothenburg, Sweden
,
AK Elf
3   Sahlgrenska University Hospital, Department of Surgery, Gothenburg, Sweden
,
H Fagman
2   Sahlgrenska University Hospital, Department of Clinical Pathology and Genetics, Gothenburg, Sweden
,
P Hedenström
4   Sahlgrenska University Hospital, Unit of Gastrointestinal Endoscopy, Göteborg, Sweden
› Author Affiliations
Further Information

Publication History

Publication Date:
23 April 2020 (online)

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    Aims A reliable preoperative grading of pancreatic neuroendocrine tumors (PanNET) is important to assess the prognosis and to determine the clinical managment - surgical resection vs active follow-up. EUS-guided fine-needle biopsy sampling (EUS-FNB) is a promising tool for this task.

    Methods In a single-center, prospective setting 2012-2019, all patients with suspected PanNETs referred for EUS-FNB (22 gauge Procore-needle) were eligible for inclusion. The diagnostic sensitivity of EUS-FNB was calculated. Then, the EUS-FNB specimens were analyzed, using a computer software aimed for digital cell counting, with respect to the biopsy quality (cell count) and the Ki67-index (Ki67-FNB). Based on the calculated Ki67-FNB, tumors were graded preoperatively (G1-G3) and compared with the corresponding surgical specimen Ki67-index (Ki67-SURG).

    Results In total, 49 unique PanNET-patients (f/m: 24/25; median tumor size:30 mm) were subjected to EUS-FNB. EUS-FNB was diagnostic in 40/49 (82%) cases. In diagnostic FNB-specimens, the biopsy quality was high (>2000 cells), moderate (1000-2000 cells), low (500-1000 cells), and very low (0-500 cells), in 19/40 (48%), 10/40 (25%), 9/40 (23%), and 2/40 (5%) cases respectively. Tumor size or sampling route did not significantly influence biopsy quality. The median calculated Ki67-FNB was 1.5% (IQR:0.6%-4.2%). Grading of resected patients (n=20) was according to [Table 1.]

    Tab. 1

    Preoperative and post-surgery grading of resected PanNETs.

    Ki67-SURG G1

    Ki67-SURG G2

    Ki67-FNB G1

    5

    6

    Ki67-FNB G2

    0

    3

    Non-diagnostic FNB/Ki67-FNB failure

    1

    5

    Undergrading was non-significantly more common in cell counts < 2000 cells versus >2000 cells (63% vs 29%, p=ns).

    Conclusions EUS-FNB performed with a 22 gauge needle is sensitive for the diagnosis of PanNET but relatively inaccurate for preoperative grading of PanNETs based on Ki67-indexing. There is a clear need for improvement in FNB-needle design to optimize core volume. Future studies on this topic is warranted.


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