Diagnostic performance and factors influencing the accuracy of EUS-FNA of pancreatic neuroendocrine neoplasms

Endoscopic Ultrasound-Guided Fine Needle Acquisition for Evaluation of Pancreatic Neuroendocrine Tumors: A Meta-Analysis

AIMS

The aim of this meta-analysis was to assess the diagnostic performance of EUS-FNA/B in patients with panNETs.

METHODS

We conducted a computerized search of the MEDLINE and Embase databases to identify relevant articles. The primary outcomes involved grading concordance rate, diagnostic rate, and correlation coefficient (Cohen's κ) for FNA/B samples compared with surgical specimens. Secondary outcomes included sample adequacy, mean number of passes, and adverse events.

RESULTS

Forty-five studies involving 2978 patients were finally included. The pooled concordance rate between EUS-FNA/B and surgical grading was 0.77 (95% CI: 0.73-0.80; I2 =48.2%). A significantly higher level of concordance was observed in G1 subgroup (0.88, 95% CI: 0.84-0.91), whereas the G2 subgroup revealed the lowest level of agreement (0.59, 95% CI: 0.52-0.65; P < 0.001). Pooled diagnostic rate for FNA/B sampling was 0.83 (95% CI: 0.79-0.86; I2 =63.3%). In addition, FNB outperformed FNA in terms of sample adequacy (0.93 for FNB vs. 0.81 for FNA; P =0.007) and number of needle passes required (2.53 for FNB vs. 3.32 for FNA; P =0.013). Moreover, the overall level of agreement for grading was moderate (κ=0.59, 95% CI: 0.49-0.68; I2 =84.5%). There were a limited number of adverse events that had minor influence on patient outcomes (0.03, 95% CI: 0.02-0.05; I2 =19.2%).

CONCLUSIONS

EUS-FNA/B is a reliable approach for the diagnosis and preoperative grading of panNET, with FNB demonstrating superior performance compared with FNA.

Evaluating endoscopic ultrasound-guided tissue acquisition for diagnosis of small pancreatic neuroendocrine neoplasms

Background and study aims Although small hypervascular tumors are suspected to be pancreatic neuroendocrine tumors (p-NENs), their diagnosis and treatment are challenging. This study evaluated the usefulness of endoscopic ultrasound-guided tissue acquisition (EUS-TA) for diagnosis of small p-NENs. Methods All p-NEN lesions that underwent EUS-TA at our hospital between April 2018 and December 2023 were retrospectively analyzed. The diagnostic sensitivity of EUS-TA and the concordance rate of grading with EUS-TA and surgical specimens were examined. The lesions were grouped by size. Results The diagnostic sensitivity of EUS-TA was analyzed for 82 lesions, of which 44 were compared with postoperative specimens for grading. The definitive diagnosis was neuroendocrine tumor (NET) in 75 lesions, neuroendocrine carcinoma in five lesions, and mixed neuroendocrine non-neuroendocrine neoplasm in two lesions. Thirty tumors were ≤10 mm, 30 were 10 to 20 mm, and 22 were >20 mm, and the diagnostic sensitivities were 96.7%, 96.7%, and 90.9%, respectively. Concordance rates for grading were 94.4%, 82.4%, and 77.8% for tumors ≤10 mm, 10 to 20 mm, and ≥20 mm, respectively, with Cohen's kappa coefficients of 0.64, 0.48, and 0.40, respectively. Conclusions EUS-TA showed adequate diagnostic sensitivity and grading agreement for p-NENs of all sizes, allowing for determination of appropriate treatment.

Recent developments in the diagnosis of pancreatic neuroendocrine neoplasms

INTRODUCTION

Pancreatic Neuroendocrine Neoplasms (PanNENs) are characterized by a highly heterogeneous clinical and biological behavior, making their diagnosis challenging. PanNENs diagnostic work-up mainly relies on biochemical markers, pathological examination, and imaging evaluation. The latter includes radiological imaging (i.e. computed tomography [CT] and magnetic resonance imaging [MRI]), functional imaging (i.e. 68Gallium [68 Ga]Ga-DOTA-peptide PET/CT and Fluorine-18 fluorodeoxyglucose [18F]FDG PET/CT), and endoscopic ultrasound (EUS) with its associated procedures.

AREAS COVERED

This review provides a comprehensive assessment of the recent advancements in the PanNENs diagnostic field. PubMed and Embase databases were used for the research, performed from inception to October 2023.

EXPERT OPINION

A deeper understanding of PanNENs biology, recent technological improvements in imaging modalities, as well as progresses achieved in molecular and cytological assays, are fundamental players for the achievement of early diagnosis and enhanced preoperative characterization of PanNENs. A multimodal diagnostic approach is required for a thorough disease assessment.

Robotic pancreatic tumor enucleation by the double bipolar technique using the da Vinci SP system: An initial case report with a technical detail

Pancreatic tumor enucleation is a procedure that can preserve pancreatic function and is sometimes performed using a minimally invasive approach. Recently, a single-port robotic platform called da Vinci SP has been developed. However, the technical details of pancreatic tumor enucleation using da Vinci SP have not been reported to date. We report a male patient in his 70s who underwent robotic SP pancreatic tumor enucleation for a pancreatic neuroendocrine tumor. The dissection between the tumor and pancreatic parenchyma was performed using the double bipolar technique. The operative time was 139 min, and the estimated blood loss was 4 mL. The patient had an uneventful recovery and was discharged on the sixth day after the surgery. Robotic SP pancreatic tumor enucleation appears to be a feasible procedure with lower invasiveness and better cosmesis.

Avoid non-diagnostic EUS-FNA: a DNN model as a possible gatekeeper to distinguish pancreatic lesions prone to inconclusive biopsy

OBJECTIVE

This work aimed to explore the utility of CT radiomics with machine learning for distinguishing the pancreatic lesions prone to non-diagnostic ultrasound-guided fine-needle aspiration (EUS-FNA).

METHODS

498 patients with pancreatic EUS-FNA were retrospectively reviewed [Development cohort: 147 pancreatic ductal adenocarcinoma (PDAC); Validation cohort: 37 PDAC]. Pancreatic lesions not PDAC were also tested exploratively. Radiomics extracted from contrast-enhanced CT was integrated with deep neural networks (DNN) after dimension reduction. The receiver operating characteristic (ROC) curve, and decision curve analysis (DCA) were performed for model evaluation. And, the explainability of the DNN model was analyzed by integrated gradients.

RESULTS

The DNN model was effective in distinguishing PDAC lesions prone to non-diagnostic EUS-FNA (Development cohort: AUC = 0.821, 95% CI: 0.742-0.900; Validation cohort: AUC = 0.745, 95% CI: 0.534-0.956). In all cohorts, the DNN model showed better utility than the logistic model based on traditional lesion characteristics with NRI >0 (p < 0.05). And, the DNN model had net benefits of 21.6% at the risk threshold of 0.60 in the validation cohort. As for the model explainability, gray-level co-occurrence matrix (GLCM) features contributed the most averagely and the first-order features were the most important in the sum attribution.

CONCLUSION

The CT radiomics-based DNN model can be a useful auxiliary tool for distinguishing the pancreatic lesions prone to nondiagnostic EUS-FNA and provide alerts for endoscopists preoperatively to reduce unnecessary EUS-FNA.

ADVANCES IN KNOWLEDGE

This is the first investigation into the utility of CT radiomics-based machine learning in avoiding non-diagnostic EUS-FNA for patients with pancreatic masses and providing potential pre-operative assistance for endoscopists.

Safety and Diagnostic Yield of Endoscopic Ultrasound-Guided Fine-Needle Biopsy for Hypervascular Pancreatic Lesions

Endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) is a common technique for diagnosing pancreatic lesions with high accuracy and a low incidence of procedural adverse events. However, occasional adverse events, particularly bleeding, may occur. Procedures for hypervascular lesions are considered important, but their risks are unknown. We aimed to evaluate the safety and diagnostic yield of EUS-FNB for hypervascular pancreatic solid lesions. This study included 301 patients with 308 solid pancreatic lesions who underwent EUS-FNB between May 2011 and December 2018. We performed propensity-score matching to balance clinical differences between hypervascular and hypovascular lesions and analyzed 52 lesions. We compared the safety and diagnostic performance of propensity score-matched cohorts. The sensitivity, specificity, and accuracy rates of EUS-FNB for hypervascular lesions were 94.7%, 100%, and 96.2%, and those for hypovascular lesions were 80.0%, 100%, and 84.6%, respectively. There was no difference in diagnostic performance between hypervascular and hypovascular lesions. Furthermore, adverse events occurred in only one patient (pancreatitis) in the hypovascular group. There were no significant differences in the occurrence of adverse events between hypervascular and hypovascular lesions (0% vs. 3.8%, p = 1.000). Therefore, EUS-FNB may be safe with a high diagnostic yield, even for hypervascular solid pancreatic lesions.

The Ki67 index evaluation of pancreatic neuroendocrine tumors using 3D immunohistochemistry in small tissue specimens

BACKGROUND

/Objectives: This study aimed to evaluate the usefulness of three-dimensional (3D) immunohistochemistry for the Ki67 index of small tissue specimens of pancreatic neuroendocrine tumor (PanNET).

METHODS

Clinicopathological materials from 17 patients with PanNET who underwent surgical resection at Jichi Medical University Hospital were analyzed. We compared the Ki67 index of endoscopic ultrasonography-fine-needle aspiration biopsy (EUS-FNAB) specimens, surgical specimens, and small tissue specimens hollowed from paraffin blocks of surgical specimens that were substituted for EUS-FNAB specimens ("sub-FNAB"). The sub-FNAB specimens were optically cleared using LUCID (IlLUmination of Cleared organs to IDentify target molecules) and analyzed using 3D immunohistochemistry.

RESULTS

The median Ki67 index in FNAB, sub-FNAB, and surgical specimens with conventional immunohistochemistry were 1.2% (0.7-5.0), 2.0% (0.5-14.6), and 5.4% (1.0-19.4), respectively. The median Ki67 index in sub-FNAB specimens with tissue clearing was calculated separately using the total number of cells on multiple images ("multiple slice"), with the image of the fewest positive cells ("coldspot"), and with the image of most positive cells ("hotspot"), which were 2.7% (0.2-8.2), 0.8% (0-4.8), and 5.5% (2.3-12.4), respectively. PanNET grade evaluated for the hotspot of the surgical specimens was significantly more consistent with those of the hotspot than multiple images of sub-FNAB specimens (16/17 vs. 10/17, p = 0.015). Hotspot evaluation using 3D immunohistochemistry of the sub-FNAB specimens showed agreement with the assessment of the surgical specimens (Kappa coefficient: 0.82).

CONCLUSIONS

Tissue clearing and 3D immunohistochemistry for the Ki67 index can potentially improve the preoperative evaluation of EUS-FNAB specimens of PanNET in routine clinical practice.

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.

Tumor Location in the Head/Uncinate Process and Presence of Fibrosis Impair the Adequacy of Endoscopic Ultrasound-Guided Tissue Acquisition of Solid Pancreatic Tumors

Endoscopic ultrasound-guided tissue acquisition (EUS-TA) of solid pancreatic tumors shows optimal specificity despite fair sensitivity, with an overall suboptimal diagnostic yield. We aim to quantify the adequacy and accuracy of EUS-TA and assess predictive factors for success, focusing on the presence and degree of specimen fibrosis. All consecutive EUS-TA procedures were retrieved, and the specimens were graded for sample adequacy and fibrosis. The results were evaluated according to patients' and tumor characteristics and the EUS-TA technique. In total, 407 patients (59% male, 70 [63-77] year old) were included; sample adequacy and diagnostic accuracy were 90.2% and 94.7%, respectively. Fibrosis was significantly more represented in tumors located in the head/uncinate process (p = 0.001). Tumor location in the head/uncinate (OR 0.37 [0.14-0.99]), number of needle passes ≥ 3 (OR 4.53 [2.22-9.28]), and the use of cell block (OR 8.82 [3.23-23.8]) were independently related to adequacy. Severe fibrosis was independently related to false negative results (OR 8.37 [2.33-30.0]). Pancreatic tumors located in the head/uncinate process showed higher fibrosis, resulting in EUS-TA with lower sample adequacy and diagnostic accuracy. We maintain that three or more needle passes and cell block should be done to increase the diagnostic yield.

Endoscopic ultrasound-guided side-fenestrated needle biopsy sampling is sensitive for pancreatic neuroendocrine tumors but inadequate for tumor grading: a prospective study

Accurate pretreatment grading of pancreatic neuroendocrine tumors (PanNETs) is important to guide patient management. We aimed to evaluate endoscopic ultrasound-guided fine needle biopsy sampling (EUS-FNB) for the preoperative diagnosis and grading of PanNETs. In a tertiary-center setting, patients with suspected PanNETs were prospectively subjected to 22-gauge, reverse-bevel EUS-FNB. The EUS-FNB samples (Ki-67_EUS) and corresponding surgical specimens (Ki-67_SURG) were analyzed with Ki-67 indexing and thereafter tumor grading, (GRADE_EUS) and (GRADE_SURG) respectively. In total 52 PanNET-patients [median age: 66 years; females: 25/52; surgical resection 22/52 (42%)] were included. EUS-FNB was diagnostic in 44/52 (85%). In 42 available FNB-slides, the median neoplastic cell count was 1034 (IQR: 504-3667) with 32/42 (76%), 22/42 (52%), and 14/42 (33%) cases exceeding 500, 1000, and 2000 neoplastic cells respectively. Ki-67_SURG was significantly higher compared to Ki-67_EUS with a moderate correlation comparing Ki-67_EUS and Ki-67_SURG (Pearson r = 0.60, r² = 0.36, p = 0.011). The GRADE_EUS had a weak level of agreement (κ = 0.08) compared with GRADE_SURG. Only 2/12 (17%) G2-tumors were correctly graded in EUS-FNB-samples. EUS-guided fine needle biopsy sampling is sensitive for preoperative diagnosis of PanNET but biopsy quality is relatively poor. Therefore, the approach seems suboptimal for pretreatment grading of PanNET.

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

Endoscopic ultrasonography‐guided tissue acquisition (EUS‐TA) is now an established technique to obtain the pathological diagnosis of solid pancreatic lesions (SPLs), but the diagnosis of small SPLS by EUS‐TA can still be difficult. We conducted a literature review and a meta‐analysis on the diagnostic yield of EUS‐TA according to the tumor size. In a meta‐analysis of 33 studies with 6883 cases, a pooled odds ratio (OR) of sensitivity was significantly higher in SPLs of >20 mm (OR 1.64, p = 0.02) and in SPLs of >10 mm (OR 3.05, p = 0.01), but not in SPLs of >30 mm (OR 1.18, p = 0.46). The meta‐analysis of accuracy also showed a similar trend: OR of 1.59 in SPLs of >20 mm (p < 0.01) and OR of 3.27 in SPLs of >10 mm (p < 0.01) and OR of 1.03 in SPLs of >30 mm (p = 0.87). The use of a 25‐gauge needle tended to improve sensitivity in small SPLs, though not statistically significant: OR of 1.25 and 2.82 in studies with and without a 25‐gauge needle (p = 0.08). The use of fine needle biopsy needles, slow pull method, and rapid on‐site evaluation did not significantly improve sensitivity in small SPLs. EUS‐TA for small SPLs, especially neuroendocrine neoplasms, is reported to have a high risk of adverse events. In summary, the diagnostic yield and safety of EUS‐TA for small (<20 mm) SPLs still needs improvement, and the best needle and technique for small SPLs should be further investigated.

The Role of EUS and EUS-FNA in Differentiating Benign and Malignant Gallbladder Lesions

Endoscopic ultrasonography (EUS) has greater spatial resolution than other diagnostic imaging modalities. In addition, if gallbladder lesions are found and gallbladder cancer is suspected, EUS is an indispensable modality, enabling detailed tests for invasion depth evaluation using the Doppler mode and ultrasound agents. Furthermore, for gallbladder lesions, EUS fine-needle aspiration (EUS-FNA) can be used to differentiate benign and malignant forms of conditions, such as xanthogranulomatous cholecystitis, and collect evidence before chemotherapy. EUS-FNA is also useful for highly precise and specific diagnoses. However, the prevention of bile leakage, an accidental symptom, is highly important. Advancements in next-generation sequencing (NGS) technologies facilitate the application of multiple parallel sequencing to EUS-FNA samples. Several biomarkers are expected to stratify treatment for gallbladder cancer; however, NGS can unveil potential predictive genomic biomarkers for the treatment response. It is believed that NGS may be feasible with samples obtained using EUS-FNA, further increasing the demand for EUS-FNA.

Comparison of Histological Sample Volumes among Various Endoscopic Ultrasound-Guided Biopsy Needles

Endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) enables easy and accurate pathological assessment. Here, we compared and assessed the area of samples on glass slides for three needle types: a 19-gauge Franseen needle (Acquire, Boston Scientific, Natick, MA, USA), a 22-gauge Franseen needle, and a 19-gauge fine-needle aspiration (FNA) needle (EZ Shot 3 Plus; Olympus, Tokyo, Japan). Among patients with suspected pancreatic cancer, with a ≥20 mm tumor located in the pancreatic body and tail, and who underwent EUS-FNA or FNB between June 2018 and March 2020, 10 were randomly selected to test each needle. The areas of histological tissue and blood clot samples were measured using the BZ-X800 imaging software (Keyence Corporation, Osaka, Japan). Baseline patient characteristics and pathological sample data showed no significant differences among the needles. The 19-gauge Franseen needle obtained significantly more histological tissue samples than the 19-gauge conventional needle (p = 0.010) and 22-gauge Franseen needle (p = 0.008). Conversely, there was no significant difference between the 19-gauge conventional needle and 22-gauge Franseen needle (p = 0.838) in this regard. The 19-gauge Franseen needle could collect more samples than the other needles, contributing to giving a more precise pathological diagnosis and more information, including genomic profiling.

Endoscopic ultrasound fine needle biopsy was not more cost-effective than fine-needle aspiration with rapid on-site evaluation in gastrointestinal lesions diagnosis

BACKGROUND AND AIM

Cost-effectiveness comparison between endoscopic ultrasound (EUS)-guided acquisition techniques by fine-needle aspiration (FNA) and fine needle biopsy (FNB) in gastrointestinal lesions is still scarce. EUS-FNB has been shown to be more cost-effective than EUS-FNA, however, when adding rapid on-site evaluation (ROSE) to EUS-FNA, it is unclear whether EUS-FNB remains more cost-effective. Our aim was to assess cost-efficacy of EUS-FNB as compared to EUS-FNA with ROSE in gastrointestinal lesions.

METHOD

All patients who underwent EUS-FNA with ROSE or EUS-FNB at Galilee Medical Center were retrospectively reviewed. Cost-effectiveness analysis was based on the additional EUS sessions needed and on the average cost expenditure to achieve one final pathological diagnosis.

RESULTS

Seventy-four cases were included in the final analysis. Of them, 21 patients (28.4%) were in the EUS-FNB group (group A), as compared to 53 patients (71.6%) who underwent EUS-FNA with ROSE (group B). Additional EUS sessions needed to achieve one final pathological diagnosis were needed in 14.3% of group A patients vs 9.4% in group B patients (P = .5). and, the average cost for achieving one final pathological diagnosis was similar in both groups (1226 ± 369$ for group A vs 1158 ± 309.6.7$ for group B, P = .2). Notably, even after analyzing pancreatic and non-pancreatic gastrointestinal lesions separately, there was no cost benefit of EUS-FNB over EUS-FNA with ROSE.

CONCLUSIONS

Cost-effectiveness analysis was not different between EUS-FNB vs EUS-FNA with ROSE. Thus, the preference of one modality over the other should be based on availability and local expertise.

Role of Endoscopic Ultrasound in the Diagnosis of Pancreatic Neuroendocrine Neoplasms

Although pancreatic neuroendocrine neoplasms (PNENs) are relatively rare tumors, their number is increasing with advances in diagnostic imaging modalities. Even small lesions that are difficult to detect using computed tomography or magnetic resonance imaging can now be detected with endoscopic ultrasound (EUS). Contrast-enhanced EUS is useful, and not only diagnosis but also malignancy detection has become possible by evaluating the vascularity of tumors. Pathological diagnosis using EUS with fine-needle aspiration (EUS-FNA) is useful when diagnostic imaging is difficult. EUS-FNA can also be used to evaluate the grade of malignancy. Pooling the data of the studies that compared the PNENs grading between EUS-FNA samples and surgical specimens showed a concordance rate of 77.5% (κ-statistic = 0.65, 95% confidence interval = 0.59–0.71, p < 0.01). Stratified analysis for small tumor size (2 cm) showed that the concordance rate was 84.5% and the kappa correlation index was 0.59 (95% confidence interval = 0.43–0.74, p < 0.01). The evolution of ultrasound imaging technologies such as contrast-enhanced and elastography and the artificial intelligence that analyzes them, the evolution of needles, and genetic analysis, will further develop the diagnosis and treatment of PNENs in the future.

Endoscopic ultrasound-guided fine-needle aspiration for the diagnosis and grading of pancreatic neuroendocrine tumors: a retrospective analysis of 110 cases

BACKGROUND

Data on the reliability of the Ki-67 index and grading calculations from endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of pancreatic neuroendocrine tumors (PanNETs) are controversial. We aimed to assess the accuracy of these data compared with histology.

METHODS

Cytological analysis from EUS-FNA in patients with suspected PanNETs (n = 110) were compared with resection samples at a single institution. A minimum of 2000 cells were considered to be adequate for grading. Correlation and agreement between cytology and histology in grading and Ki-67 values, respectively, were investigated. Secondary outcomes included the diagnostic performance of EUS-FNA.

RESULTS

EUS-FNA samples were adequate for PanNET diagnosis and PanNET grading in 98/110 (89.1 %) and 77/110 (70.0 %) patients, respectively; thus, 77 samples were adequate for comparing cytology vs. histology. There were 67 (62.0 %), 40 (36.4 %), and 1 (0.9 %) patients with a final diagnosis of G1, G2, and G3 tumors, respectively. EUS-FNA grading was concordant with surgical pathology in 81.8 % of patients; under- and overgrading occurred in 15.6 % and 2.6 %, respectively. The overall level of agreement for grading was moderate (Cohen's κ = 0.59, 95 % confidence interval [CI] 0.34 - 0.78). Spearman's rho for Ki-67 in tumors ≤ 20 mm and > 20 mm was strong and moderate, respectively (rho = 0.68, 95 %CI 0.47 - 0.83; rho = 0.59, 95 %CI 0.35 - 0.75). The Bland - Altman plot showed that the Ki-67 values were comparable and reproducible between the two measurements.

CONCLUSIONS

Although they were not available for a significant number of patients, grading and Ki-67 values from cytology correlated with histology moderately to strongly.

Comparison of prognosis between observation and surgical resection groups with small sporadic non-functional pancreatic neuroendocrine neoplasms without distant metastasis

BACKGROUND

The treatment of small (≤ 2 cm), sporadic localized non-functional pancreatic neuroendocrine neoplasms (PNENs) is often controversial. This study aimed to investigate the clinical outcomes with observation and surgical resection in small PNENs.

METHODS

Seventy-five patients with small localized sporadic non-functional PNENs ≤ 2 cm, who underwent observation or surgical resection, were retrospectively reviewed. Changes in tumor size during follow-up in the observation group were also investigated.

RESULTS

The median age of the cohort was 61 (range 35-81) years. The tumor grades were G1, G2, and unknown, in 61 (81.3%), 8 (10.7%), and 6 (8.0%) patients, respectively. The mean follow-up periods in the observation (n = 23) and surgical resection groups (n = 52) were 52.3 (range 6.8-133.3) months and 73.0 (range 9.1-179.9) months, respectively. The median overall survival was not reached. During follow-up, no patient died of PNENs, two died of other diseases, three had lymph node metastases, and one experienced recurrence after surgical resection. There was no significant difference in overall survival between the observation and surgical resection groups (hazard ratio: 0.031, P = 0.417). The mean change in tumor size in the observation group was + 0.30 mm (range - 1.6 to + 3.0 mm). No deaths, tumor progression, lymph node metastases, distant metastases, or recurrence were noted in patients with PNENs ≤ 1 cm (n = 36).

CONCLUSIONS

The prognosis of small localized PNENs is good. Observation may be an alternative to surgery in high-risk patients and those with small G1 tumors, particularly those measuring ≤ 1 cm.

Endoscopic ultrasound-guided tissue sampling of pancreatic lesions

Important advancements in endoscopic ultrasound-guided tissue sampling techniques and development of new needle designs have improved the diagnostic yield of pancreatic lesions. This innovation in endoscopic ultrasound has also opened the door for early diagnosis and precision therapy in the management of cancer patients. Endoscopic ultrasound fine needle biopsy is an invaluable tool and newer biopsy designs will probably play a pivotal role in the management of pancreatic lesions in the next future. Aim of the current review was to provide an overview on the available techniques and devices for the endoscopic ultrasound-guided sampling of pancreatic solid and cystic lesions.

Workup of Gastroenteropancreatic Neuroendocrine Tumors

Neuroendocrine tumors of the gastrointestinal tract or pancreas are rare. Their presentation overlaps with other intra-abdominal neoplasms, but can have unique features. The workup involves recognition of unusual clinical features associated with the tumors, imaging, analysis of blood or urine concentrations, and biopsy. Functional imaging takes advantage of the neuroendocrine tumor-specific expression of somatostatin receptors. There are characteristic features supporting the diagnosis on contrast-enhanced cross-sectional imaging. The use of tumor markers for biochemical diagnosis requires an understanding of the confounding variables affecting these assays. There are unique and specific immunohistochemical staining and grading requirements for appropriate diagnosis of these tumors.

Diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration: A single-center analysis

Background: Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) has become an important modality for identification of intra-abdominal masses. This study analyzed the accuracy of EUS-FNAB in a single medical center and explored factors related to positive diagnosis. Materials and methods: In total, 77 patients with EUS-FNAB were retrospectively reviewed from July 2016 to February 2020. "Atypical (tends to be neoplasm/malignancy)," "suspicious (first consider neoplasm/malignancy)," and "malignant" were defined as positive cytology. The final diagnoses were based on histopathologic examination. The positive rate of EUS-FNAB for the diagnosis of neoplasm and its associations with age, sex, target puncture mass size, liver function, tumor markers, albumin, hypertension, and diabetes were examined. Results: Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of EUS-FNAB cytologic diagnoses in all patients were 77.9% (60/77), 76.1% (54/71), 100%, 100%, and 26.1% (6/23), respectively. Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of EUS-FNAB cytologic diagnoses in the pancreas were 80.0% (48/60), 79.3% (46/58), 100%, 100%, and 14.3% (2/14), respectively. The results of EUS-FNAB in pancreatic masses showed that the level of CA19-9 was higher in the true positive group than in the false-negative group (p<0.05). There were no factors associated with the true positive cytologic diagnoses (p>0.05). Conclusions: Our single-medical center study showed that EUS-FNAB is an accurate diagnostic procedure for the evaluation of intra-abdominal masses. Further follow-up is required to explore factors associated with the true positive cytology.

Endoscopic ultrasound-guided fine-needle aspiration vs fine-needle biopsy for the diagnosis of pancreatic neuroendocrine tumors

Background and study aims  Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) as a method of obtaining preoperative diagnosis of pancreatic neuroendocrine tumors (PanNETs) has been reported in several series. Fine-needle biopsies (FNB) are increasingly employed to obtain core specimens during EUS. However, the differences in efficacy between these sampling methods in the diagnosis of PanNETs still needs to be defined. Patients and methods  Over a 13-year period, all patients who underwent EUS-guided tissue sampling of suspicious pancreatic lesions with clinical, endoscopic and pathologic details were entered into an electronic database. Lesions underwent EUS-FNA or FNB sampling, or a combination of the two. The accuracy and safety of different EUS-guided sampling methods for confirmed PanNETs were investigated. Results  A total of 91 patients (M/F: 42/49, median age: 57 years), who underwent 102 EUS procedures had a final diagnosis of PanNET. Both EUS-guided sampling modalities were used in 28 procedures, EUS-FNA alone was used in 61 cases, while EUS-FNB alone in 13 cases. Diagnostic yield of EUS-FNA and EUS-FNB alone, including the inadequate specimens, was 77.5 % (95 %CI: 68.9 - 86.2 %) and 85.4 % (95 %CI: 74.6 - 96.2 %), respectively. The combination of both sampling modalities established the diagnosis in 96.4 % of cases (27/28) (95 %CI: 89.6 - 100 %), significantly superior to EUS-FNA alone ( P  = 0.023). Diagnostic sensitivity among the adequate samples for EUS-FNA, EUS-FNB and for the combination of the two methods was 88.4 % (95 %CI: 80.9 - 96.0 %), 94.3 % (95 %CI: 86.6 - 100 %) and 100 % (95 %CI: 100 - 100 %). There was one reported complication, a post-FNA bleeding, treated conservatively. Conclusions  EUS-FNB improves diagnostic sensitivity and confers additional information to cytological assessment of PanNETs.

A rational approach to postoperative surveillance for resected non-functional pancreatic neuro-endocrine tumours

BACKGROUND

Non-functional pancreatic neuroendocrine tumours (NF-PNETs) are rare and have highly variable outcomes. Current guidelines recommend surveillance for NF-PNETs <2 cm. Patients who ultimately have surgical resection are at risk of disease recurrence, and data to support postoperative surveillance protocols are lacking. The aims of this study were to i) identify post-operative predictors of recurrence and ii) risk stratify patients at risk of recurrence.

METHODS

Consecutive patients who underwent surgery for NF-PNETs between 2002 and 2015 were identified retrospectively. Data were collected on demographics, pre-operative laboratory results and histopathological tumour characteristics. Statistical analyses were based on penalised Cox-regression modelling and a decision-tree model. Comparison of the variables identified was performed using ROC curves to identify the most sensitive and specific variable associated with disease recurrence.

RESULTS

We identified 73 patients (38 males) with a median age of 61.5 years (range: 31-79). The median period of follow-up was 49 months (5-131). During follow up, 10 deaths (13.9%) were recorded and disease recurrence occurred in 12 patients (16.4%). The Kaplan-Meier predicted 1-,3- and 5-year recurrence-free survival rates were 98.6% (95% CI = 95.9, 100%), 85.4% (76.9-94.8%) and 72% (58.7-88.2%) respectively. Cox multivariate analysis identified poor tumour differentiation (WHO G3 grade) and lymph node ratio (LNR) as independent predictors for recurrence (p < 0.05). A simple criterion of 'tumour grade G3 or LNR ≥0.1' was found to be sensitive and specific in detecting disease recurrence.

CONCLUSION

Our results have identified a simple and sensitive criterion for risk stratifying post-resection surveillance. Prospective validation in larger patient cohort is now warranted.

Endoscopic ultrasound-guided sampling of solid pancreatic masses: the fine needle aspiration or fine needle biopsy dilemma. Is the best needle yet to come?

Fine needle aspiration (FNA) is currently the standard of care for sampling pancreatic solid masses by using endoscopic ultrasound (EUS). The accuracy of the technique is reported to be high, especially if coupled with the rapid on site evaluation (ROSE), and it has a high safety profile. However, FNA presents some limitations, such as the small amount of tissue that can be collected and the inability of obtaining a core tissue with intact histological architecture, which is relevant to perform immunohistochemical analysis, molecular profiling and, therefore, targeted therapies. Moreover, the presence of the ROSE by an expert cytopathologist is very important to maximize the diagnostic yield of FNA technique; however, it is not widely available, especially in small centers. Hence, the introduction of EUS fine needle biopsy (FNB) with a new generation of needles, which show a high safety profile too and a satisfying diagnostic accuracy even in the absence of ROSE, could be the key to overcome the limitations of FNA. However, FNB has not yet shown diagnostic superiority over FNA. Considering all the technical aspects of FNA and FNB, the different types of needle currently available, comparisons in term of diagnostic yield, and the different techniques of sampling, a tailored approach should be used in order to determine the needle that is most appropriate for the different specific scenarios.

Endoscopic ultrasonography for pancreatic solid lesions

The incidence and mortality rates of pancreatic cancer, which has a poor prognosis, are rising rapidly. Endoscopic ultrasonography (EUS) provides superior spatial resolution compared with other imaging modalities such as transabdominal ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI), and it is considered among the most reliable and efficient diagnostic modalities for pancreatic diseases. In this review, we show that EUS is useful for detection of pancreatic solid lesions and staging of pancreatic cancer. EUS also plays an important role in screening patients with high-risk factors for pancreatic cancer. Although EUS is useful for detection of small pancreatic lesions, pancreatic lesions are difficult to characterize using this modality, because most pancreatic solid lesions appear hypoechoic on EUS. From this point of view, contrast-enhanced harmonic EUS (CH-EUS) plays an important role in the differential diagnosis of pancreatic lesions. EUS and CH-EUS are also useful for staging pancreatic cancer. Moreover, EUS-guided fine-needle aspiration (EUS-FNA) is superior to other modalities in terms of cytopathological diagnosis. Although EUS-FNA has a high diagnostic ability for pancreatic cancer, the combination of EUS-FNA and CH-EUS improves the diagnostic ability by decreasing the number of false-negative cases. Thus, conventional EUS, EUS-FNA, and CH-EUS are essential in clinical practice for the diagnosis of pancreatic solid lesions.

Accuracy of EUS and CEH EUS for the diagnosis of pancreatic tumours

OBJECTIVES

The main objective is to compare the accuracy of EUS and CEH EUS for the diagnosis of pancreatic cancer (PC). The secondary objective is to evaluate the accuracy of EUS FNA and to determine to what extent EUS and CEH EUS findings are affected by endosonographer subjectivity.

METHODS

A prospective single-centre study was conducted in patients with pancreatic lesions detected on CT. The patients were examined by EUS, CEH EUS and EUS FNA. The obtained results were compared with the final diagnosis that was based on cytology and further clinical findings and on histopathological findings from subjects who underwent surgery. A second reading of the EUS and CEH EUS images was performed by the endosonographer, who was blinded to clinical data of patients.

RESULTS

We examined 116 patients, 73 had a final diagnosis of PC, 14 had NETs and 20 had other tumours. The sensitivity, specificity, NPV, PPV, and accuracy of EUS for diagnosis of PC were 83.1, 62.5, 83.1, 70.7 and 78.6%, for CEH EUS 94.5, 61.7, 84.1, 84 and 84.1% and for EUS FNA 87.6, 91.2, 95.5, 77.5 and 88.8, respectively. The inter-observer agreement for EUS marker of PC was good (κ = 0.75), and that for CEH EUS was average (κ = 0.59 for arterial phase and κ = 0.68 for washout in venous phase).

CONCLUSION

CEH EUS is a non-invasive method that allows more accurate identification of PC than EUS. The subjectivity of CEH EUS evaluation is worse than that of EUS but acceptable.

Efficacy of 3 fine-needle biopsy techniques for suspected pancreatic malignancies in the absence of an on-site cytopathologist

BACKGROUND AND AIMS

EUS-guided fine-needle aspiration/biopsy (EUS-FNA/B) has a high diagnostic accuracy for pancreatic tumors. Most reports have focused on the diagnostic yield of cytology or histology; the ability of various FNA/B techniques to obtain an adequate mass of cells or tissue has rarely been investigated.

METHODS

Patients with suspected pancreatic malignancy underwent EUS-FNB using a 22-gauge ProCore needle by either the stylet slow-pull-back technique (group A), conventional negative suction after stylet removal (group B), or non-suction after stylet removal (group C) in the absence of an on-site cytopathologist. The adequacy of the 3 techniques based on the diagnostic yield, cellularity, blood contamination, and core-tissue acquisition was evaluated.

RESULTS

A total of 50 patients (27 males) were analyzed. The mean tumor size was 21 to 40 mm in 54%. The rate of a good or excellent proportion of cellularity was highest in group A compared with groups B and C (72% vs 60% vs 50%, P = .049). A >25% rate of blood contamination was more prevalent in group B (30% vs 42% vs 10%, P = .009). The rate of adequate core-tissue acquisition was not different (52% vs 34% vs 50%, P = .140). Based on the multivariate generalized estimation equation, the stylet slow-pull-back technique and a tumor size >40 mm were favorable factors for diagnostic adequacy.

CONCLUSIONS

The stylet slow-pull-back technique might enable acquisition of tissue and assessment of cellularity for the diagnosis of pancreatic tumors suspected to be malignant. (Clinical trial registration number: KCT0002190.).

A retrospective histological comparison of EUS-guided fine-needle biopsy using a novel franseen needle and a conventional end-cut type needle

Background and Objectives:

Recently, a 22G Franseen needle for EUS-guided fine-needle biopsy (EUS-FNB) with three novel symmetric heels has been developed to adequately obtain a core tissue.

Methods:

All 38 consecutive patients with pancreatic masses who underwent EUS-FNB using a Franseen needle were investigated retrospectively to assess the efficacy and safety of EUS-FNB using the Franseen needle. Then, the EUS-FNB outcomes and histological assessments of the tissue obtained by EUS-FNB using the Franseen needle and EUS-FNA using the conventional end-cut type needle for each of the 30 pancreatic ductal adenocarcinoma cases were compared.

Results:

An accurate histological diagnosis of the Franseen needle was achieved with a mean of 2 passes in 97.4% of patients. Although the accurate histological diagnosis rate of pancreatic ductal adenocarcinoma was not significantly different (96.7% vs. 93.3%, P = 0.55), the mean number of passes in the Franseen needle was significantly less than that in the conventional needle (2.1 ± 0.4 vs. 3.2 ± 0.8, P < 0.001). The presence of desmoplastic fibrosis with neoplastic cellular elements and venous invasion were significantly higher (96.7% vs. 40.0%, P < 0.001 and 23.3% vs. 0%, P < 0.01, respectively) and the amount of obtained tissue was significantly larger with the Franseen needle (2.13 mm²vs. 0.45 mm², P < 0.001).

Conclusions:

EUS-FNB using the Franseen needle enables the acquisition of a larger amount of tissue sample and achieves an accurate histological diagnosis with a smaller number of passes than the conventional end-cut type needle.

A Combined Nomogram Model to Preoperatively Predict Histologic Grade in Pancreatic Neuroendocrine Tumors

PURPOSE

The purpose of this study is to develop and validate a nomogram model combing radiomics features and clinical characteristics to preoperatively differentiate grade 1 and grade 2/3 tumors in patients with pancreatic neuroendocrine tumors (pNET).Experimental Design: A total of 137 patients who underwent contrast-enhanced CT from two hospitals were included in this study. The patients from the second hospital (n = 51) were selected as an independent validation set. The arterial phase in contrast-enhanced CT was selected for radiomics feature extraction. The Mann-Whitney U test and least absolute shrinkage and selection operator regression were applied for feature selection and radiomics signature construction. A combined nomogram model was developed by incorporating the radiomics signature with clinical factors. The association between the nomogram model and the Ki-67 index and rate of nuclear mitosis were also investigated respectively. The utility of the proposed model was evaluated using the ROC, area under ROC curve (AUC), calibration curve, and decision curve analysis (DCA). The Kaplan-Meier (KM) analysis was used for survival analysis.

RESULTS

An eight-feature-combined radiomics signature was constructed as a tumor grade predictor. The nomogram model combining the radiomics signature with clinical stage showed the best performance (training set: AUC = 0.907; validation set: AUC = 0.891). The calibration curve and DCA demonstrated the clinical usefulness of the proposed nomogram. A significant correlation was observed between the developed nomogram and Ki-67 index and rate of nuclear mitosis, respectively. The KM analysis showed a significant difference between the survival of predicted grade 1 and grade 2/3 groups (P = 0.002).

CONCLUSIONS

The combined nomogram model developed could be useful in differentiating grade 1 and grade 2/3 tumor in patients with pNETs.

Imaging of pancreatic neuroendocrine tumors: recent advances, current status, and controversies

INTRODUCTION

Recently, there have been a number of advances in imaging pancreatic neuroendocrine tumors (panNETs), as well as other neuroendocrine tumors (NETs), which have had a profound effect on the management and treatment of these patients, but in some cases are also associated with controversies. Areas covered: These advances are the result of numerous studies attempting to better define the roles of both cross-sectional imaging, endoscopic ultrasound, with or without fine-needle aspiration, and molecular imaging in both sporadic and inherited panNET syndromes; the increased attempt to develop imaging parameters that correlate with tumor classification or have prognostic value; the rapidly increasing use of molecular imaging in these tumors and the attempt to develop imaging parameters that correlate with treatment/outcome results. Each of these areas and the associated controversies are reviewed. Expert commentary: There have been numerous advances in all aspects of the imaging of panNETs, as well as other NETs, in the last few years. The advances are leading to expanded roles of imaging in the management of these patients and the results being seen in panNETs/GI-NETs with these newer techniques are already being used in more common tumors.

Serum Elastase 1 Level as a Risk Factor for Postoperative Recurrence in Patients with Well-Differentiated Pancreatic Neuroendocrine Neoplasms

PURPOSE

This study was designed to assess the potential role of the preoperative serum level of elastase 1 as a risk factor for recurrence in patients with resectable well-differentiated pancreatic neuroendocrine neoplasms (PanNETs).

METHODS

Preoperative serum elastase 1 levels were measured in 53 patients with PanNETs who underwent complete tumor resection in two tertiary referral centers between January 2004 and June 2017. The preoperative elastase 1 levels were correlated with clinicopathological characteristics, including tumor recurrence and recurrence-free survival.

RESULTS

The median elastase 1 level was 96 ng/dL (range: 21-990 ng/dL). Preoperative serum elastase 1 levels were significantly higher in those with tumors ≥ 20 mm in diameter (vs. < 20 mm, P = 0.018), WHO grade 2 (vs. grade 1, P = 0.035), and microscopic venous invasion (vs. without venous invasion, P = 0.039). The median preoperative serum level of elastase 1 was higher in patients with recurrence than in those without recurrence (251 vs. 80 ng/dL, P = 0.004). Receiver operating characteristic analysis of elastase 1 levels showed that a cutoff level of 250 ng/dL was associated with postoperative recurrence, with 63% sensitivity, 100% specificity, and 94% overall accuracy. Patients with higher elastase 1 levels showed significantly worse recurrence-free survival than that of those with lower levels (2-year recurrence-free survival rate: 25% and 92%, respectively, P < 0.001).

CONCLUSIONS

Our data provide the first evidence that high preoperative elastase 1 levels may be a risk factor for postoperative recurrence in patients with resectable PanNETs.

Clinical impact of endoscopic ultrasonography on the management of neuroendocrine tumors: lights and shadows

The incidence of gastroenteropancreatic neuroendocrine neoplasms has increased in the recent decades. An extensive bibliographical search was performed in PubMed to identify guidelines and primary literature (retrospective and prospective studies, systematic reviews, case series) published mostly between year 1997 and June 2017, using both medical subject heading (MeSH) terms and free-language keywords about the accuracy and diagnostic and therapeutic role of endoscopic ultrasound in the context of gastro-entero-pancreatic neuroendocrine neoplasms. Endoscopic ultrasound is the modality of choice for diagnosing pancreatic neuroendocrine neoplasms and for the locoregional staging of gastric, duodenal, pancreatic and rectal neuroendocrine neoplasms; in particular, in the setting of pancreatic neuroendocrine neoplasms it has demonstrated higher accuracy in tumor detection than other imaging modalities. Furthermore, the possibility of tattooing pancreatic lesions by endoscopic ultrasound fine needle aspiration may help surgeons to locate the tumor and avoid any demolition surgery. Finally, endoscopic ultrasound-guided therapies have been proposed and used in several studies for patients unsuitable for surgery, with good results on the control of symptoms and the reduction of tumor burden.

The diagnostic value of FNA biopsy in grading pancreatic neuroendocrine tumors

BACKGROUND

There has been much controversy regarding the accuracy of grading pancreatic neuroendocrine tumors (PNETs) on fine-needle aspiration (FNA) biopsy. The objectives of this study were to evaluate whether grading according to the fraction of Ki-67-positive tumor cells (the Ki-67 proliferation index) on material from endoscopic ultrasound-guided FNA biopsies correlated with grading on surgical resection specimens and to evaluate the minimum amount of FNA material needed.

METHODS

A case series of 27 PNETs with FNA biopsies and corresponding surgical resection specimens at the authors' institution were evaluated. Tumors were graded on FNA and surgical specimens with an evaluation of Ki-67 index according to 2010 World Health Organization criteria. Chart reviews were conducted to evaluate recurrence or clinical progression in patients who were being managed conservatively with observation.

RESULTS

The evaluation of grading between FNA and tumor resection specimens revealed that 22 of 26 FNA specimens (84.6%) had Ki-67 results comparable to those in the corresponding surgical resection specimens, thus allowing for accurate grading. Correct FNA diagnosis with the ability to distinguish between grade 1 and 2 tumors had a positive predictive value of 88.9%, with 72.7% sensitivity, 93.3% specificity, and a P value of .00081. In addition, 24 of 26 cases contained less than 2000 cells, of which 20 were correctly graded on FNA material. Seven of 26 FNA samples had less than 1000 cells, of which 6 were correctly graded, including 2 that had only 50 cells.

CONCLUSIONS

The current results exhibit good correlation between FNA grade and final grade on surgical resection specimens using Ki-67 index, even in samples with less than the recommended total cell count. Therefore, grading of PNETs on FNA with the Ki-67 proliferation index should be assessed and is a practical parameter to report to clinicians. Cancer Cytopathol 2018;126:170-8. © 2017 American Cancer Society.

Treatment challenges in and outside a specialist network setting: Pancreatic neuroendocrine tumours

Pancreatic Neuroendocrine Neoplasms comprise a group of rare tumours with special biology, an often indolent behaviour and particular diagnostic and therapeutic requirements. The specialized biochemical tests and radiological investigations, the complexity of surgical options and the variety of medical treatments that require individual tailoring, mandate a multidisciplinary approach that can be optimally achieved through an organized network. The present study describes currents concepts in the management of these tumours as well as an insight into the challenges of delivering the pathway in and outside a Network.

Multimodal Treatment of Vasoactive Intestinal Polypeptide-producing Pancreatic Neuroendocrine Tumors with Liver Metastases

A 53-year-old man presented with diarrhoea and hypokalaemia and was diagnosed with a neuroendocrine tumour of unknown origin with multiple liver metastases. Somatostatin analogues led to a reduction in the size of the tumours and improvement of his symptoms. However, after several years, the tumours grew in size, and the patient's clinical symptoms recurred. The patient underwent transcatheter arterial embolization (TAE) of the hepatic artery to treat the liver metastases. Immediately after embolization, the symptoms disappeared. Although the patient had an unresectable vasoactive intestinal polypeptide-producing neuroendocrine tumour, the endocrine symptoms were able to be controlled with chemotherapy and TAE, resulting in a long-term survival.

B-mode and contrast-enhancement characteristics of small nonincidental neuroendocrine pancreatic tumors

BACKGROUND AND OBJECTIVES

Imaging of the pancreas for detection of neuroendocrine tumors is indicated as surveillance in multiple endocrine neoplasia type 1 (MEN1) or if typical clinical symptoms combined with hormone production raise the suspicion of a neuroendocrine tumor. Endoscopic ultrasound (EUS) is considered the best imaging modality to detect small pancreatic tumors. However, little is known about how small pancreatic neuroendocrine tumors (pNETs) present on EUS.

PATIENTS AND METHODS

In this multicenter study, we retrospectively analyzed the endosonographic characteristics of small pNETs which had been detected due to typical biochemistry and clinical symptoms or during surveillance of MEN 1. Only small pancreatic tumors ≤15 mm with histological confirmation as pNET were included. B-mode and contrast-enhanced ultrasound- and EUS patterns were analyzed.

RESULTS

Among 32 patients with histologically proven small pNETs, 7 patients had known MEN1. Among the pNETs, 20 were insulinoma, 2 gastrinoma, 3 glucagonoma, 6 nonfunctional in MEN1, and one PPoma. 94% of the pNET appeared hypoechogenic, only 1 isoechogenic and 1 hyperechogenic. After contrast injection, 90% of the pNETS showed hyperenhancement compared to the surrounding pancreatic parenchyma.

CONCLUSION

The high spatial resolution of EUS allows detection and even cytological confirmation of pNET <7 mm diameter. Hypoechogenicity in B-mode and hyperenhancement after injection of contrast agents are endosonographic characteristics of small pNET and present in >90% of pNETs.

Advances in the diagnosis and treatment of pancreatic neuroendocrine neoplasms in Japan

Several new developments have occurred in the field of pancreatic neuroendocrine neoplasm (PNEN) recently in Japan. First, the utility of chromogranin A (CgA), useful for the diagnosis and monitoring of the treatment response of neuroendocrine neoplasm (NEN), has been demonstrated in Japan. For PNEN diagnosis and treatment, grading and correct histological diagnosis according to the WHO 2010 classification is important. Regarding the histological diagnosis, the advent of endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) has enabled correct pathological diagnosis and suitable treatment for the affected tissue. Furthermore, EUS-FNA has also facilitates the assessment of the presence or absence of gene mutations. In addition, patients who have a well-differentiated neuroendocrine tumor (NET) showing a Ki-67 index of higher than 20 % according to the WHO 2010 classification, have also been identified, and their responses to treatment were found to be different from those of patients with poorly differentiated neuroendocrine carcinoma (NEC). Therefore, the concept of NET G3 was proposed. Additionally, somatostatin receptor type 2 is expressed in several cases of NET, and somatostatin receptor scintigraphy (¹¹¹In-octreoscan) has also been approved in Japan. This advancement will undoubtedly contribute to the localization diagnosis, the identification of remote metastasis, and assessments of the treatment responses of PNEN. Finally, regarding the treatment strategy for PNEN, the management of liver metastasis is important. The advent of novel molecular-targeted agents has dramatically improved the prognosis of advanced PNEN. Multimodality therapy that accounts for the tumor stage, degree of tumor differentiation, tumor volume, and speed of tumor growth is required.

Endoscopic ultrasound-guided fine needle aspiration of pancreatic lesions with 22 versus 25 Gauge needles: A meta-analysis

BACKGROUND

Robust data in favour of a clear superiority of 22 versus 25 Gauge needles for endoscopic ultrasound-guided fine needle aspiration are still lacking.

OBJECTIVE

We aimed to compare the diagnostic sensitivity, specificity and safety of these two needles for endoscopic ultrasound-guided fine needle aspiration of solid pancreatic lesions.

METHODS

A computerized bibliographic search was restricted to randomized controlled trials only. Pooled effects were calculated using a random-effects model and expressed in terms of risk ratio and 95% confidence interval.

RESULTS

We analysed seven trials with 689 patients and 732 lesions (295 sampled with 22 Gauge needle, 309 with 25 Gauge needle, and 128 with both needles). A non-significant superiority of 25 Gauge in terms of pooled sensitivity (risk ratio: 0.93, 0.91-0.95 versus 0.89, 0.85-0.94 of 22 Gauge needle; p = 0.13) and no difference in terms of specificity (1.00, 0.98-1.00 in both groups; p = 0.85) were observed. Sample adequacy was similar between the two devices (risk ratio: 1.03, 0.99-1.06; p = 0.15). Very few adverse events were observed and did not impact on patient outcomes.

CONCLUSION

Our meta-analysis reveals non-superiority of 25 Gauge over 22 Gauge; hence no definitive recommendations over the use of one particular device can be made.

Slow-pull and different conventional suction techniques in endoscopic ultrasound-guided fine-needle aspiration of pancreatic solid lesions using 22-gauge needles

AIM

To evaluate the cytological diagnostic capacity and sample quality of the slow-pull technique and compare them with different suction techniques.

METHODS

From July 2010 to December 2015, 102 patients with pancreatic solid lesions who underwent endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) with 22-gauge needles were retrospectively evaluated. EUS-FNA diagnosis was based on a cytological examination, and final diagnosis was based on a comprehensive standard of cytological diagnosis, surgical pathology and clinical or imaging follow-up. Cytological specimens were characterized for cellularity and blood contamination. The cytological diagnostic capacity and sample quality of the slow-pull technique and suction techniques with 5-mL/10-mL/20-mL syringes were analyzed.

RESULTS

Of all of the EUS-FNA procedures, the slow-pull technique and suction techniques with 5-mL/10-mL/20-mL syringes were used in 31, 19, 34 and 18 procedures, respectively. There were significant differences between these four suction techniques in terms of cytological diagnostic accuracy (90.3% vs 63.2% vs 58.8% vs 55.6%, P = 0.019), sensitivity (88.2% vs 41.7% vs 40.0% vs 36.4%, P = 0.009) and blood contamination (score ≥ 2 for 29.0% vs 52.6% vs 70.6% vs 72.2%, P = 0.003). The accuracy and sensitivity of the slow-pull technique were significantly higher than those of the suction techniques using 5-mL (P = 0.03, P = 0.014), 10-mL (P = 0.005; P = 0.006) and 20-mL syringes (P = 0.01, P = 0.01). Blood contamination was significantly lower in the slow-pull technique than in the suction techniques with 10-mL (P = 0.001) and 20-mL syringes (P = 0.007).

CONCLUSION

The slow-pull technique may increase the cytological diagnostic accuracy and sensitivity with slight blood contamination during EUS-FNA when using 22-gauge needles for solid pancreatic masses.

Current progress in diagnosis and therapy of neuroendocrine neoplasms of the digestive system

Neuroendocrine neoplasms (NENs) are a group of heterogeneous, biologically diverse, rare malignancies originated from the peptidergic neurons and neuroendocrine cells. In recent years, the incidence of NENs has been increasing gradually. They typically arise in the pancreas and gastrointestinal tract. Chromogranin A (CgA) has long been used as an important broad-spectrum marker for the identification of NENs. The diagnosis is based on histopathology demonstrating neuroendocrine features such as positive staining for chromogranin A and specific hormones such as gastrin, proinsulin, vasoactive intestinal peptide (VIP) and glucagon. In addition, radiological modalities including computed tomography (CT), positron emission tomography and computed tomography (PET/CT), magnetic resonance imaging (MRI), ultrasound (US), endoscopic ultrasound (EUS), and somatostatin receptor scintigraphy (SRS) can help establish a diagnosis. Surgery is still one of the cornerstones in the management of NENs. This article reviews the current progress in the diagnosis and therapy of NENs of the digestive system, including the pathological features and clinical diagnostic modalities for primary esophageal, gastric, duodenal, small intestinal, appendiceal, colonic, rectal, hepatic, gallbladder, extrahepatic bile duct, and pancreatic NENs, according to a revised system of classification, nomenclature and grading of NENs proposed by the fourth edition of "World Health Organization (WHO) classification of tumours of the digestive system" in 2010, and consensus of diagnosis and treatment of gastroenteropancreatic NENs (GEP-NENs) proposed by the Chinese Society of Clinical Oncology (CSCO) in 2013.