EUS-guided tissue acquisition: Do we need to shoot for a "core" to score?

Fine Needle Aspiration versus Fine Needle Biopsy of Biliopancreatic Lesions: Are They Really Opposing Techniques or Can They Be Complementary? Our Experience in a Large Cohort of Cases from a Single Institution

INTRODUCTION

Nowadays, endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA), and fine needle biopsy (FNB) are considered the best procedures for the diagnosis of biliopancreatic lesions. These methods represent a milestone since they proved to be both safe for the patient and useful to achieve diagnostic material useful to plan the best treatment strategy.

OBJECTIVE

Since in the literature, a debate between cytology and histology supporters is still ongoing and the trend is changing in favor of FNB, we would like to present our experience about the diagnostic yield of FNA and FNB. The aim of our study is to highlight FNA versus FNB diagnostic role of biliopancreatic lesions, highlight advantages, and drawbacks of these procedures, and our view on these 2 procedures and whether they should still be considered complementary or opposing techniques.

METHODS

We retrospectively reviewed our hospital series of 469 EUS diagnostics procedures of biliopancreatic lesions performed in 419 patients, between 2015 and 2019.

RESULTS

The overall adequacy rates of FNA and FNB were, respectively, 98.9 and 100%. Stratifying cases according to anatomic location of the mass (pancreas vs. biliary system), we detected 168 malignancies out of 349 pancreatic lesions (168/349; 48.1%), while biliary system cases positive for malignancy represented 33.8% (23/68 cases) (p value = 0.045, χ2 test). As for concomitant FNB, our series displayed a high rate of diagnostic concordance (88.8%).

CONCLUSIONS

Despite numerous data published, it is still unclear which is the most feasible method to use; therefore, we compared FNA, FNB, or their combination to understand the best applicable technique. Our experience confirmed that FNA is extremely efficient in the diagnosis of biliopancreatic lesions, especially in the hands of expert endoscopists and pathologists. Considering anatomic location, EUS-FNA is more accurate for mass-forming neoplasms in the pancreatic parenchyma rather than for lesions of the biliary system. Moreover, concomitant FNB usually confirmed the cytological diagnosis, allowing a deeper immunohistochemical characterization of the neoplasia. This proves that a "pure" cytology and "pure" histology approach should be looked differently since these are complementary techniques especially if we can obtain a cellblock from FNA.

Present and Future of Endoscopic Ultrasound-Guided Tissue Acquisition in Solid Pancreatic Tumors

Endoscopic ultrasound-guided tissue acquisition (EUS-TA) is a well-established method for pathological diagnosis of solid pancreatic neoplasm. It can be performed either as EUS-guided fine-needle aspiration (EUS-FNA) or EUS-guided fine-needle biopsy (EUSFNB). The incidence of adverse events related to EUS-TA is less than 1%. The factors that affect the diagnostic accuracy and specimen adequacy include the techniques used, type and size of the needle, competency of endosonographers, presence of cytopathologists/ cytotechnologists, and rapid on-site examination. EUS-TA may contribute to precision medicine through obtaining tissue samples for next-generation sequencing. The current status, several clinical issues for diagnostic yield and adverse events, and future perspectives of EUS-FNA/FNB for diagnosing pancreatic neoplasm have been discussed in this review article.

Fine-needle biopsy is superior to fine-needle aspiration of suspected gastrointestinal stromal tumors: a large multicenter study

Background and study aims  There are numerous studies published on the diagnostic yield of the new fine-needle biopsy (FNB) needles in pancreas masses. However, there are limited studies in suspected gastrointestinal stromal tumors (GIST lesions). The aim of this study was to evaluate the diagnostic yield of a new fork-tip FNB needle. Patients and methods  This was a multicenter retrospective study of consecutive patients from prospectively maintained databases comparing endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) versus endoscopic ultrasound-guided FNB (EUS-FNB) using the fork-tip needle. Outcomes measured were cytopathology yield (ability to obtain tissue for analysis of cytology), ability to analyze the tissue for immunohistochemistry (IHC yield), and diagnostic yield (ability to provide a definitive diagnosis). Results  A total of 147 patients were included in the study of which 101 underwent EUS-FNB and 46 patients underwent EUS-FNA. Median lesion size in each group was similar (21 mm vs 25 mm, P  = 0.25). Cytopathology yield, IHC yield, and diagnostic yield were 92 % vs 46 % ( P  = 0.001), 89 % vs 41 % ( P  = 0.001), and 89 % vs 37 % ( P  = 0.001) between the FNB and FNA groups, respectively. Median number of passes was the same between the two groups at 3.5. Conclusion  EUS-FNB is superior to EUS-FNA for diagnostic yield of suspected GIST lesions. This should be confirmed with a prospective study.

Touch imprint cytology on endoscopic ultrasound fine-needle biopsy provides comparable sample quality and diagnostic yield to standard endoscopic ultrasound fine-needle aspiration specimens in the evaluation of solid pancreatic lesions

OBJECTIVES

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the gold standard for the diagnosis of solid pancreatic lesions (SPLs). Cytological samples can also be obtained using touch imprint cytology (TIC) on EUS fine-needle biopsy (FNB) specimens. We aimed to compare sample quality and diagnostic yield of EUS-FNA-standard cytology (EUS-FNA-SC) to that of EUS-FNB-TIC in a series of patients with SPLs.

METHODS

Thirty-two consecutive patients referred for EUS-tissue acquisition of SPLs who underwent rapid on-site evaluation of both EUS-FNA-SC and paired EUS-FNB-TIC during the same endoscopic session were retrospectively identified. Sample quality (evaluated in terms of blood contamination, presence of clots, tissue casts, cellularity, and necrosis) and diagnostic yield were compared between the techniques.

RESULTS

The mean number of passes to reach diagnosis at rapid on-site evaluation was similar between EUS-FNA-SC and EUS-FNB-TIC (1.09 ± 0.3 vs 1.13 ± 0.34, P = .711). EUS-FNA-SC scores of sample quality were comparable to those of EUS-FNB-TIC (blood contamination, 2.47 ± 1.11 vs 2.25 ± 1.14, P = .109; clots, 1.25 ± 0.76 vs 1.19 ± 0.69, P = .624; tissue casts, 3.56 ± 0.88 vs 3.59 ± 1.09, P = .872; cellularity, 2.84 ± 1.11 vs 3.09 ± 1.09, P = .244; necrosis, 2.25 ± 1.08 vs 2.53 ± 1.02 P = .059; total score, 12.38 ± 2.88 vs 17.66 ± 2.38, P = .536). Adequacy, sensitivity and diagnostic accuracy of the two sampling techniques were equal (93.7%, 90.6% and 90.6%, respectively).

CONCLUSIONS

EUS-FNB-TIC provides comparable samples to those of EUS-FNA-SC and combines the benefits of cytology and histology for the evaluation of SPLs by employing a single needle during the same endoscopic procedure.

Prospective histological evaluation of a 20G core trap with a forward-cutting bevel needle for EUS-FNA of pancreatic lesions

BACKGROUND

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has been established as a method to obtain tissues of various organs. To obtain sufficient tissue has clinical impact to facilitate the diagnosis by clinical pathologists, the assessment and subtyping of various neoplasms, and for further immunohistochemical investigations of tumor type. Recently, a novel 20G core trap with a forward-cutting beveled FNA needle (ProC-F) has become available. The aim of this prospective study was to evaluate the feasibility and diagnostic yield of EUS-FNA for pancreatic lesions using this needle.

PATIENTS AND METHOD

In this study, the first puncture was performed using the ProC-F. Only tissue obtained with the first puncture using the ProC-F was used to evaluate diagnostic yield of ProC-F. The second puncture was performed using a 22G standard FNA needle using the same technique as for the first puncture. Second puncture was performed if the endosonographer did not feel that sufficient tissue had not been obtained by first puncture.

RESULTS

Fifty-three consecutive patients who underwent EUS-FNA for pancreatic lesions were prospectively enrolled. The technical success rate of EUS-FNA using the ProC-F was 98.1% (52/53). The rate of adequate tissue obtained by ProC-F was 96.2% (50/52). On the other hand, the rate of adequate tissue obtained by the standard needle was 71.1%. The sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy of the ProC-F and the standard needle were 92.5, 100, 100, 76.9, and 94.0%, and 85.2, 100, 100, 55.6, and 87.5%, respectively. Diagnostic yield of ProC-F about sensitivity (P = 0.027), NPV (P = 0.035), and accuracy (P = 0.004) was significantly higher than of standard needle. Adverse events were not seen in any patients.

CONCLUSIONS

Although only tissue obtained by the first puncture was evaluated, the rate of adequate tissue and the histologic diagnostic yield for pancreatic lesions were extremely high using the ProC-F.

Advanced EUS Guided Tissue Acquisition Methods for Pancreatic Cancer

Pancreas cancer is a lethal cancer as the majority patients are diagnosed at an advanced incurable stage. Despite improvements in diagnostic modalities and management strategies, including surgery and chemotherapies, the outcome of pancreas cancer remains poor. Endoscopic ultrasound (EUS) is an important imaging tool for pancreas cancer. For decades, resected pancreas cancer and other cancer specimens have been used to identify tissue biomarkers or genomics for precision therapy; however, only 20% of patients undergo surgery, and thus, this framework is not useful for unresectable pancreas cancer. With advancements in needle technologies, tumor specimens can be obtained at the time of tissue diagnosis. Tumor tissue can be used for development of personalized cancer treatment, such as performing whole exome sequencing and global genomic profiling of pancreas cancer, development of tissue biomarkers, and targeted mutational assays for precise chemotherapy treatment. In this review, we discuss the recent advances in tissue acquisition of pancreas cancer.

Increasing Number of Passes Beyond 4 Does Not Increase Sensitivity of Detection of Pancreatic Malignancy by Endoscopic Ultrasound-Guided Fine-Needle Aspiration

BACKGROUND & AIMS

It is not clear exactly how many passes are required to determine whether pancreatic masses are malignant using endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). We aimed to define the per-pass diagnostic yield of EUS-FNA for establishing the malignancy of a pancreatic mass, and identify factors associated with detection of malignancies.

METHODS

In a prospective study, 239 patients with solid pancreatic masses were randomly assigned to groups that underwent EUS-FNA, with the number of passes determined by an on-site cytopathology evaluation or set at 7 passes, at 3 tertiary referral centers. A final diagnosis of pancreatic malignancy was made based on findings from cytology, surgery, or a follow-up evaluation at least 1 year after EUS-FNA. The cumulative sensitivity of detection of malignancy by EUS-FNA was calculated after each pass; in the primary analysis, lesions categorized as malignant or suspicious were considered as positive findings.

RESULTS

Pancreatic malignancies were found in 202 patients (84.5% of the study population). EUS-FNA detected malignancies with 96% sensitivity (95% confidence interval [CI], 92%-98%); 4 passes of EUS-FNA detected malignancies with 92% sensitivity (95% CI, 87%-95%). Tumor size greater than 2 cm was the only variable associated with positive results from cytology analysis (odds ratio, 7.8; 95% CI, 1.9-31.6). In masses larger than 2 cm, 4 passes of EUS-FNA detected malignancies with 93% sensitivity (95% CI, 89%-96%) and in masses ≤2 cm, 6 passes was associated with 82% sensitivity (95% CI, 61%-93%). Sensitivity of detection did not increase with increasing number of passes.

CONCLUSIONS

In a prospective study, we found 4 passes of EUS-FNA to be sufficient to detect malignant pancreatic masses; increasing the number of passes did not increase the sensitivity of detection. Tumor size greater than 2 cm was associated with malignancy, and a greater number of passes may be required to evaluate masses 2 cm or less. ClinicalTrials.gov number, NCT01386931.