Endoscopic ultrasonography‐guided tissue acquisition for small solid pancreatic lesions: Does the size matter?

The outcomes of endoscopic ultrasound-guided tissue acquisition for small focal liver lesions measuring ≤2 cm

Objectives

Endoscopic ultrasound-guided tissue acquisition (EUS-TA) for focal liver lesions has gained attention as an alternative to percutaneous biopsy. Although the outcomes of EUS-TA for focal liver lesions have been reported to be favorable, no studies have focused on small focal liver lesions (≤2 cm). The aim of this study was to evaluate the outcomes of EUS-TA for small focal liver lesions (≤2 cm).

Methods

The details of EUS-TA performed for focal liver lesions between 2016 and 2022 were retrospectively reviewed. The outcomes were compared between cases involving ≤2 cm lesions and those involving >2 cm lesions. The primary outcomes were diagnostic ability and adverse events.

Results

EUS-TA for focal liver lesions was performed in 109 cases. Of the 109 cases, 32 (29.3%) involved ≤2 cm lesions and 77 (70.6%) involved >2 cm lesions. Right lobe lesions and transduodenal puncture were significantly fewer in the ≤2 cm group. There were no significant differences in needle gauge, needle type, or number of punctures between the groups. The sensitivity, specificity, and accuracy rates were 96.8%, 100%, and 96.8%, respectively, in the ≤2 cm group and 97.4%, 100%, and 97.4%, respectively, in the >2 cm group, with no significant differences between the groups. There was no difference in adverse events between the groups (0% in the ≤2 cm group and 2.3% in the >2 cm group).

Conclusions

EUS-TA for small focal liver lesions measuring ≤2 cm has favorable outcomes, which are similar to those for lesions measuring >2 cm.

Randomized trial comparing the Franseen needle versus 2 types of sharpened-tip 3-prong needles in EUS-guided tissue acquisition from solid pancreatic lesions

BACKGROUND AND AIMS

EUS-guided tissue acquisition (EUS-TA) is crucial for diagnosing pancreatic diseases. Recently, 2 novel types of sharpened-tip, 3-prong fine-needle biopsy (FNB) needles, the Trident needle (Micro-Tech Endoscopy, High Wycombe, UK) and the 3-point needle (TopGain; MediGlobe, London, UK), were developed to improve puncture performance. In this study, these novel needles were compared with the conventional Franseen needle in EUS-TA from solid pancreatic lesions (SPLs).

METHODS

In this prospective, multicenter, randomized controlled trial, patients with SPLs ≥10 mm were randomized for use of either conventional or novel FNB needles. The primary endpoint was the tissue collection rate, and secondary endpoints were histologic diagnosis, tissue volume, initial puncture success, puncture performance, and adverse events.

RESULTS

One hundred eighty-five patients were analyzed. The tissue collection rates were 96.8% for the conventional needle and 92.6% for the novel FNB needles. The novel needles presented slightly lower tissue collection rates, although this difference was not statistically significant. Furthermore, this difference was -4.2% (90% CI, -9.53 to 1.12), which did not indicate noninferiority. However, the novel needles significantly outperformed the conventional needles in terms of initial puncture success and overall puncture performance. No significant differences were found in histologic diagnosis, tissue volume, or adverse events between the groups.

CONCLUSIONS

The conventional FNB needle demonstrated a higher tissue collection rate but did not surpass the noninferiority margin that was set in this study, with no significant differences in the histologic diagnostic performance or tissue volume between the needles. The superior puncture performance of the novel needles suggests their particular benefit in challenging cases or for less-experienced endoscopists. (Clinical trial registration number: jRCT1042220099.).

Endoscopic Ultrasound-Guided Pancreatic Tissue Sampling: Lesion Assessment, Needles, and Techniques

Endoscopic ultrasound (EUS)-guided tissue sampling includes the techniques of fine needle aspiration (FNA) and fine needle biopsy (FNB), and both procedures have revolutionized specimen collection from the gastrointestinal tract, especially from remote/inaccessible organs. EUS-FNB has replaced FNA as the procedure of choice for tissue acquisition in solid pancreatic lesions (SPLs) across various society guidelines. FNB specimens provide a larger histological tissue core (preserving tissue architecture) with fewer needle passes, and this is extremely relevant in today's era of precision and personalized molecular medicine. Innovations in needle tip design are constantly under development to maximize diagnostic accuracy by enhancing histological sampling capabilities. But, apart from the basic framework of the needle, various other factors play a role that influence diagnostic outcomes, namely, sampling techniques (fanning, aspiration or suction, and number of passes), collection methods, on-site evaluation (rapid, macroscopic, or visual), and specimen processing. The choice taken depends strongly on the endoscopist's preference, available resources at the disposal, and procedure objectives. Hence, in this review, we explicate in detail the concepts and available literature at our disposal on the topic of EUS-guided pancreatic tissue sampling to best guide any practicing gastroenterologist/endoscopist in a not-to-ideal set-up, which EUS-guided tissue acquisition technique is the "best" for their case to augment their diagnostic outcomes.

Effectiveness of endoscopic ultrasound-guided tissue acquisition with stereomicroscopic on-site evaluation for preoperative diagnosis of resectable or borderline resectable pancreatic cancer: a prospective study

BACKGROUND/AIMS

To validate endoscopic ultrasound-guided tissue acquisition (EUS-TA) used in conjunction with stereomicroscopic on-site evaluation (SOSE) as a preoperative diagnostic tool for resectable pancreatic cancer (R-PC) and borderline resectable PC (BR-PC).

METHODS

Seventy-eight consecutive patients who underwent EUS-TA for suspected R-PC or BR-PC were enrolled. The primary endpoint was the sensitivity of EUS-TA together with SOSE based on the stereomicroscopically visible white core (SVWC) cutoff value. One or two sites were punctured by using a 22-gauge biopsy needle for EUS-TA, based on the SOSE findings.

RESULTS

We collected 99 specimens from 56 and 22 patients with R-PC and BR-PC, respectively. Based on the SOSE results, we performed 57 procedures with one puncture. The SVWC cutoff values were met in 73.7% and 73.1% of all specimens and in those obtained during the first puncture, respectively. The final diagnoses were malignant and benign tumors in 76 and two patients, respectively. The overall sensitivity, specificity, and accuracy of EUS-TA for the 78 lesions were 90.8%, 100%, and 91.0%, respectively. The sensitivity for malignant diagnosis based on the SVWC cutoff value were 89.5% and 90.4% for the first puncture and all specimens, respectively.

CONCLUSIONS

The sensitivity of EUS-TA in conjunction with SOSE for malignancy diagnosis in patients with suspected R-PC or BR-PC was 90.4%.

Mcl-1 expression is a predictive marker of response to gemcitabine plus nab-paclitaxel for metastatic pancreatic cancer

Antiapoptotic protein, including Mcl-1, expression is frequently observed in pancreatic cancer. Gemcitabine plus nabpaclitaxel (GnP) is the standard chemotherapy for metastatic pancreatic cancer (MPC); however, predictive markers for its efficacy remain unestablished. This study evaluated the association between GnP's therapeutic effects and Mcl-1 expression in tissue samples obtained using endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for pancreatic tumor or percutaneous ultrasound-guided biopsy for metastatic liver tumor. We retrospectively reviewed 38 patients with histologically diagnosed MPC who received GnP as the first-line chemotherapy at our institute between December 2014 and July 2018. Post-immunohistochemistry analysis for Mcl-1 expression detection, patients were divided to into two groups based on the cell proportion showing Mcl-1 immunoreactivity: positive (> 20%; 23 [60.5%] patients) and negative (≤ 20%; 15 [39.5%] patients) groups. Clinical characteristics did not differ between the two groups. The Mcl-1 positive group showed a significantly higher disease control rate (95.7% vs. 73.3%; P = 0.046), longer progressionfree survival (PFS) (7.2 months vs. 4.9 months; P = 0.018) and longer overall survival (OS) (14.9 months vs. 9.2 months; P = 0.008) than the Mcl-1 negative group. Multivariate analysis showed that Mcl-1 expression was an independent predictive marker for PFS and OS. Mcl-1 expression could be a predictive marker for favorable response to GnP.

Oil blotting paper for formalin fixation increases endoscopic ultrasound-guided tissue acquisition-collected sample volumes on glass slides

OBJECTIVES

Endoscopic ultrasound-guided tissue acquisition (EUS-TA) is used for pathological diagnosis and obtaining samples for molecular testing, facilitating the initiation of targeted therapies in patients with pancreatic cancer. However, samples obtained via EUS-TA are often insufficient, requiring more efforts to improve sampling adequacy for molecular testing. Therefore, this study investigated the use of oil blotting paper for formalin fixation of samples obtained via EUS-TA.

METHODS

This prospective study enrolled 42 patients who underwent EUS-TA for pancreatic cancer between September 2020 and February 2022 at the Osaka International Cancer Institute. After a portion of each sample obtained via EUS-TA was separated for routine histological evaluation, the residual samples were divided into filter paper and oil blotting paper groups for analysis. Accordingly, filter paper and oil blotting paper were used for the formalin fixation process. The total tissue, nuclear, and cytoplasm areas of each sample were quantitatively evaluated using virtual slides, and the specimen volume and histological diagnosis of each sample were evaluated by an expert pathologist.

RESULTS

All cases were cytologically diagnosed as adenocarcinoma. The area ratios of the total tissue, nuclear, and cytoplasmic portions were significantly larger in the oil blotting paper group than in the filter paper group. The frequency of cases with large amount of tumor cells was significantly higher in the oil blotting paper group (33.3%) than in the filter paper group (11.9%) (p = 0.035).

CONCLUSIONS

Oil blotting paper can increase the sample volume obtained via EUS-TA on glass slides and improve sampling adequacy for molecular testing.

The impact of biliary stents on the diagnostic yield of endoscopic ultrasound-guided fine needle aspiration for solid pancreatic lesions: A single-center retrospective study and meta-analysis

Background

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is widely used for the pathological diagnosis of solid pancreatic lesions but in cases with obstructive jaundice, transpapillary sampling can be performed during endoscopic retrograde cholangiopancreatography with transpapillary biliary stent placement. Thus, it is still controversial whether EUS-FNA should be performed prior to endoscopic retrograde cholangiopancreatography with biliary stent placement or only after negative transpapillary sampling.

Methods

The accuracy, sensitivity, and specificity of EUS-FNA for solid pancreatic lesions with or without indwelling biliary stents were retrospectively studied in patients undergoing EUS-FNA between January 2017 and December 2021. We also conducted a meta-analysis including our data to compare the accuracy and sensitivity of EUS-FNA with or without biliary stents.

Results

A total of 509 patients (40 with biliary stents and 469 without biliary stents) were included. The accuracy (77.5% vs. 94.5%, p < 0.001) and sensitivity (71.0% vs. 91.7%, p < 0.001) were lower in EUS-FNA with biliary stents. A meta-analysis confirmed that accuracy (odds ratio [OR] of 0.43, 95% confidence interval [CI] 0.29-0.62, p < 0.001) and sensitivity (OR of 0.46, 95% CI 0.33-0.64, p < 0.001) were lower in EUS-FNA with biliary stents. There were no statistically significant differences between plastic stents and self-expandable metallic stents for accuracy or sensitivity.

Conclusions

The presence of biliary stents had a negative impact on the diagnostic performance of EUS-FNA, and EUS-FNA prior to endoscopic retrograde cholangiopancreatography with biliary stent placement should be considered in cases with obstructive jaundice.

Diagnostic performance of EUS-guided tissue acquisition for solid pancreatic lesions ≤10 mm

Background and Objectives

EUS tissue acquisition (EUS-TA) is the standard diagnostic method for solid pancreatic lesions (SPLs); however, there are few reports on EUS-TA results for SPLs ≤10 mm. Furthermore, given the recent advent of fine-needle biopsy, the current diagnostic accuracy of EUS-TA for SPLs ≤10 mm is unknown. This study aimed to evaluate the diagnostic accuracy and efficacy of EUS-TA for SPLs ≤10 mm.

Methods

We retrospectively analyzed the data of 109 patients with SPLs ≤10 mm who underwent EUS-TA. All patients underwent rapid on-site specimen evaluation.

Results

The median tumor diameter was 8 mm (range, 2.5-10 mm), and the technical success rate was 99.1% (108/109). Adverse events were observed in 3 patients (2.8%). The diagnostic performance was as follows: sensitivity, 90.1% (64/71); specificity, 97.3% (36/37); accuracy, 92.6% (100/108); positive predictive value, 98.5% (64/65); and negative predictive value, 83.7% (36/43). Multivariate analysis revealed that the number of punctures (odds ratio, 7.03; 95% confidence interval, 1.32-37.5; P = 0.023) and tumor type (odds ratio, 11.90; 95% confidence interval, 1.38-102.0; P = 0.024) were independent risk factors for inaccurate EUS-TA results. The diagnostic accuracy of EUS-TA for pancreatic ductal adenocarcinoma was 87.5% (14/16). No EUS-TA-related needle-tract seeding was observed in patients with pancreatic ductal adenocarcinoma during the observation period.

Conclusions

EUS-TA for SPLs ≤10 mm showed adequate diagnostic accuracy and was safe for use with rapid on-site specimen evaluation in all cases.

EUS-FNA versus EUS-FNB in Pancreatic Solid Lesions ≤ 15 mm

A small tumor size may impact the diagnostic performance of endoscopic ultrasound-guided tissue acquisition (EUS-TA) for diagnosing solid pancreatic lesions (SPLs). We aimed to compare the diagnostic yield of EUS-guided fine-needle aspiration (FNA) and biopsy (FNB) in SPLs with a diameter ≤ 15 mm. Consecutive patients who underwent EUS-TA for SPLs ≤ 15 mm between January 2015 and December 2022 in a tertiary referral center were retrospectively evaluated. The primary endpoint was diagnostic accuracy. The final diagnosis was based on surgical pathology or disease evolution after a minimum follow-up of 6 months. Inadequate samples were all considered false negatives for the study. Secondary outcomes included sample adequacy, factors impacting accuracy, and safety. We included 368 patients (52.4% male; mean age: 60.2 years) who underwent FNA in 72 cases and FNB in 296. The mean size of SPLs was 11.9 ± 2.6 mm. More than three passes were performed in 5.7% and 61.5% of patients in the FNB and FNA groups, respectively (p < 0.0001). FNB outperformed FNA in terms of diagnostic accuracy (89.8% vs. 79.1%, p = 0.013) and sample adequacy (95.9% vs. 86.1%, p < 0.001). On multivariate analysis, using FNA (OR: 2.10, 95% CI: 1.07-4.48) and a final diagnosis (OR: 3.56, 95% CI: 1.82-6.94) of benign conditions negatively impacted accuracy. Overall, the adverse event rate was 0.8%, including one pancreatitis in the FNA group and one pancreatitis and one bleeding in the FNB group, all mild and conservatively managed. EUS-TA for SPLs ≤ 15 mm has a high diagnostic yield and safety. This study suggests the superiority of FNB over FNA, with better performance even with fewer passes performed.

The application of low echo reduction in endoscopic ultrasound-guided tissue acquisition for pancreatic mass lesions

Toyonaga and colleagues demonstrate, with accompanying video, the use of low echo reduction, which is a novel endoscopic ultrasound function provided by a new endoscopic ultrasound processor that increases contrast without white-out. Low echo reduction might be useful in improving lesion boundaries and needle visibility during endoscopic ultrasound-guided tissue acquisition.

Efficacy of endoscopic ultrasound-guided tissue acquisition for solid pancreatic lesions 20 mm or less in diameter suspected as neuroendocrine tumors or requiring differentiation

BACKGROUND

For non-functioning pancreatic neuroendocrine tumors (pNETs) ≤ 20 mm, most guidelines consider follow-up observations as an option; however, the various treatment strategies are defined by size alone, even though the Ki-67 index is important for malignancy grading. Endoscopic ultrasound-guided tissue acquisition (EUS-TA) is the standard for the histopathological diagnosis of solid pancreatic lesions; however, recent results for small lesions remain unclear. Therefore, we examined the efficacy of EUS-TA for solid pancreatic lesions ≤ 20 mm suspected as pNETs or requiring differentiation and the non-increase rate in tumor size in follow-up cases.

METHODS

We retrospectively analyzed data of 111 patients (median age = 58 years) with lesions ≤ 20 mm suspected as pNETs or requiring differentiation who underwent EUS-TA. All patients underwent specimen evaluation by rapid onsite evaluation (ROSE).

RESULTS

EUS-TA led to a diagnosis of pNETs in 77 patients (69.4%) and tumors other than pNETs in 22 patients (19.8%). The histopathological diagnostic accuracy of EUS-TA was 89.2% (99/111) overall, 94.3% (50/53) for 10-20 mm lesions, and 84.5% (49/58) for ≤ 10 mm lesions, with no significant difference in diagnostic accuracy (p = 0.13). The Ki-67 index was measurable in all patients with a histopathological diagnosis of pNETs. Among 49 patients with a diagnosis of pNETs who were followed up, one patient (2.0%) showed tumor enlargement.

CONCLUSIONS

EUS-TA for solid pancreatic lesions ≤ 20 mm suspected as pNETs or requiring differentiation is safe and has adequate histopathological diagnostic accuracy, suggesting that follow-up observations of pNETs with a histological pathologic diagnosis are acceptable in the short term.

Comparison of Diagnostic Yield and Safety of Serial Pancreatic Juice Aspiration Cytologic Examination (SPACE) with Different Indications

We assessed whether there are differences in the diagnostic yield and safety of serial pancreatic juice aspiration cytologic examination (SPACE) among different indications. We retrospectively analyzed 226 patients who underwent SPACE. They were classified into group A (patients with pancreatic masses, including advanced adenocarcinoma, sclerosing pancreatitis, or autoimmune pancreatitis), group B (suspicious pancreatic carcinoma patients without obvious pancreatic masses, including small pancreatic carcinoma, carcinoma in situ, or benign pancreatic duct stenosis), and group C (intraductal papillary mucinous neoplasm, IPMN). There were 41, 66, and 119 patients, with malignancy diagnosed in 29, 14, and 22 patients, in groups A, B, and C, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 69%, 100%, 100%, 57%, and 78% in group A; 79%, 98%, 92%, 94%, and 94% in group B; and 27%, 87%, 32%, 84%, and 76% in group C, respectively. PEP was observed in three (7.3%), three (4.5%), and fifteen (13%) patients in group A, B, and C, respectively (p = 0.20). SPACE is useful and safe in patients with suspicious small pancreatic carcinoma. However, it has limited efficacy and might not be recommended in patients with IPMN because of the high frequency of PEP.