Recent Articles on Pancreatobiliary #Pathology – 2020-11-14

These are the recent articles on Pancreatobiliary Pathology:

To see all journal watch articles please visit: http://pbpath.org/journal-watch-upcoming-issue/

New Pancreas Articles


  • Reassessment of the Optimal Number of Examined Lymph Nodes in Pancreatoduodenectomy for Pancreatic Ductal Adenocarcinoma

Annals of surgery 2020 Nov;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=33177357

OBJECTIVE: To reappraise the optimal number of examined lymph nodes (ELN) in pancreatoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC).
SUMMARY BACKGROUND DATA: The well-established threshold of 15 ELN in PD for PDAC is optimized for detecting one positive node (PLN) per the previous 7 edition of the AJCC staging manual. In the framework of the 8 edition, where at least four PLN are needed for an N2 diagnosis, this threshold may be inadequate for accurate staging.
METHODS: Patients who underwent upfront PD at two academic institutions between 2000 and 2016 were analyzed. The optimal ELN threshold was defined as the cut-point associated with a 95% probability of identifying at least 4 PLN in N2 patients. The results were validated addressing the N-status distribution and stage migration.
RESULTS: Overall, 1218 patients were included. The median number of ELN was 26 (IQR 17-37). ELN was independently associated with N2-status (OR 1.27, p < 0.001). The estimated optimal threshold of ELN was 28. This cut-point enabled improved detection of N2 patients and stage III disease (58% versus 37%, p = 0.001). The median survival was 28.6 months. There was an improved survival in N0/N1 patients when ELN exceeded 28, suggesting a stage migration effect (47 versus 29 months, adjusted HR 0.649, p < 0.001). In N2 patients, this threshold was not associated with survival on multivariable analysis.
CONCLUSION: Examining at least 28 LN in PD for PDAC ensures optimal staging through improved detection of N2/stage III disease. This may have relevant implications for benchmarking processes and quality implementation.

doi: https://doi.org/10.1097/SLA.0000000000004552



  • Alterations in Ki67 Labeling Following Treatment of Poorly Differentiated Neuroendocrine Carcinomas: A Potential Diagnostic Pitfall

The American journal of surgical pathology 2020 Nov;():

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=33177340

Assessment of the Ki67 index is critical for grading well-differentiated neuroendocrine tumors (WD-NETs), which can show a broad range of labeling that defines the WHO grade (G1-G3). Poorly differentiated neuroendocrine carcinomas (PD-NECs) have a relatively high Ki67 index, >20% in all cases and commonly exceeding 50%. After anecdotally observing PD-NECs with an unexpectedly low and heterogeneous Ki67 index following chemotherapy in 5 cases, we identified 15 additional cases of treated high-grade neuroendocrine neoplasms (HG-NENs). The study cohort comprised 20 cases; 11 PD-NECs, 8 mixed adenoneuroendocrine carcinomas, and 1 WD-NET, G3 from various anatomic sites (gastrointestinal tract, pancreas, larynx, lung, and breast). The Ki67 index was evaluated on pretreatment (when available) and posttreatment samples. Topographic heterogeneity in the Ki67 index was expressed using a semi-quantitative score of 0 (no heterogeneity) to 5 (>80% difference between maximal Ki67 and minimal Ki67 indices). Relative to the pretreatment group (n=9, mean Ki67 of 86.3%, range 80% to 100%), the neoplasms in the posttreatment group (n=20, mean Ki67 of 47.7%, range 1% to 90%) showed a significantly lower Ki67 index (18/20 cases). Of the 18 cases with a relatively low Ki67 index, 15 showed heterogeneous labeling (mean heterogeneity score of 2.3, range 1 to 5) and in 3 cases it was a homogeneously low. This phenomenon was observed in all subtypes of HG-NENs. In 6 cases, the alterations in Ki67 index following treatment were sufficient to place these HG-NENs in the WHO G1 or G2 grade, erroneously suggesting a diagnosis of WD-NET, and in 9 cases there was sufficient heterogeneity in the Ki67 index to suggest that a limited biopsy may sample an area of low Ki67, even though hotspot regions with a Ki67 index of >20% persisted. In 7 cases, the alterations in the Ki67 index were accompanied by morphologic features resembling a WD-NET. These observations suggest that there is a potential for misinterpretation of previously treated PD-NECs as WD-NETs, or for assigning a lower grade in G3 WD-NETs. While the prognostic significance of treatment-associated alterations in Ki67 index is unknown, awareness of this phenomenon is important to avoid this diagnostic pitfall when evaluating treated NENs.

doi: https://doi.org/10.1097/PAS.0000000000001602



  • Efficacy of EUS-guided FNB using a Franseen needle for tissue acquisition and microsatellite instability evaluation in unresectable pancreatic lesions

BMC cancer 2020 Nov;20(1):1094

PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=33176750

BACKGROUND: The efficacy of immune checkpoint blockade in the treatment of microsatellite instability (MSI)-high tumors was recently reported. Therefore, the acquisition of histological specimens is desired in cases of unresectable solid pancreatic lesions (UR SPLs). This study investigated the efficacy of endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) using a Franseen needle for UR SPL tissue acquisition and MSI evaluation.
METHODS: A total of 195 SPL patients who underwent EUS-guided fine-needle aspiration (EUS-FNA) or EUS-FNB (EUS-FNAB) between January 2017 and March 2020 were enrolled in this study. Among them, 89 SPL patients (FNB: 28, FNA: 61) underwent EUS-FNAB using a 22-G needle (UR SPLs: 58, FNB: 22, FNA: 36) (UR SPLs after starting MSI evaluation: 23, FNB: 9, FNA: 14).
RESULTS: The puncture number was significantly lower with FNB than with FNA (median (range): 3 (2-5) vs 4 (1-8), P <  0.01, UR SPLs: 3 (2-5) vs 4 (1-8), P = 0.036). Histological specimen acquisition was more commonly achieved with FNB than with FNA (92.9% (26/28) vs 68.9% (42/61), P = 0.015, UR SPLs: 100% (22/22) vs 72.2% (26/36), P <  0.01). The histological specimen required for MSI evaluation was acquired more often with FNB than with FNA (88.9% (8/9) vs 35.7% (5/14), P = 0.03).
CONCLUSIONS: EUS-FNB using a Franseen needle is efficient for histological specimen acquisition and sampling the required amount of specimen for MSI evaluation in UR SPL patients.

doi: https://doi.org/10.1186/s12885-020-07588-5


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To see all journal watch articles please visit: http://pbpath.org/journal-watch-upcoming-issue/