Small Solid Pancreatic Lesions Research Articles

Enhanced endoscopic ultrasound imaging for pancreatic lesions: The road to artificial intelligence.

Early detection of pancreatic cancer has long eluded clinicians because of its insidious nature and onset. Often metastatic or locally invasive when symptomatic, most patients are deemed inoperable. In those who are symptomatic, multi-modal imaging modalities evaluate and confirm pancreatic ductal adenocarcinoma. In asymptomatic patients, detected pancreatic lesions can be either solid or cystic. The clinical implications of identifying small asymptomatic solid pancreatic lesions (SPLs) of < 2 cm are tantamount to a better outcome. The accurate detection of SPLs undoubtedly promotes higher life expectancy when resected early, driving the development of existing imaging tools while promoting more comprehensive screening programs. An imaging tool that has matured in its reiterations and received many image-enhancing adjuncts is endoscopic ultrasound (EUS). It carries significant importance when risk stratifying cystic lesions and has substantial diagnostic value when combined with fine needle aspiration/biopsy (FNA/FNB). Adjuncts to EUS imaging include contrast-enhanced harmonic EUS and EUS-elastography, both having improved the specificity of FNA and FNB. This review intends to compile all existing enhancement modalities and explore ongoing research around the most promising of all adjuncts in the field of EUS imaging, artificial intelligence.

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.

Endoscopic ultrasound elastography for small solid pancreatic lesions with or without main pancreatic duct dilatation

Background/Objectives: Endoscopic ultrasound elastography (EUS-EG) is useful for diagnosis of small solid pancreatic lesions (SPLs), particularly in excluding pancreatic cancer (PC), but its dependence on main pancreatic duct dilatation (MPDD) has not been examined. We aimed to investigate EUS-EG for diagnosis of small SPLs with and without MPDD. MethodsPatients with pathologically diagnosed SPLs of ≤20 mm were included and retrospectively analyzed. Using the blue:green ratio, an EUS-EG image was classified as blue-dominant, equivalent, or green-dominant. Using multiple EUS-EG images per patient, a lesion with a greater number of blue-dominant than green-dominant images was classified as stiff, and the others as soft. EUS-EG images in random order were judged by three raters. Considering stiff SPLs as PC, diagnostic performance of EUS-EG was examined for SPLs with and without MPDD. ResultsOf 126 cases analyzed, 65 (52%) were diagnosed as PC, and 63 (50%) had MPDD. A total of 1077 EUS-EG images were examined (kappa coefficient = 0.783). Lesions were classified as stiff in 91 cases and soft in 35 (kappa coefficient = 0.932). The ratio of stiff to soft lesions was significantly higher in PC than in non-PC (62:3 vs. 29:32, P < 0.001). The sensitivity, specificity, and negative predictive value of a stiff lesion with vs. without MPDD for diagnosis of PC were 94%, 23%, and 50% vs. 100%, 60%, and 100%, respectively. ConclusionsUsing the EUS-EG stiffness classification for small SPLs, PC can be excluded with high confidence and concordance for a soft lesion without MPDD.

Diagnostic Fine-Needle Biopsy of Small Solid Pancreatic Lesions Using a Franseen Needle during Endoscopic Ultrasound Examination.

Background and aim: During endoscopic ultrasound-guided fine needle aspiration biopsy (EUS-FNB), Franseen needles can help collect sufficient tissue to permit histopathological assessment. However, its efficacy might be limited by the size of the targeted lesion. This study aimed to evaluate the feasibility of histopathological assessment of small solid pancreatic lesions using a 22-gauge Franseen needle during EUS-FNB. Methods: This retrospective study evaluated data from all patients who underwent EUS-FNB using a Franseen needle for solid pancreatic lesions at the University of Toyama Hospital between June 2018 and April 2020. Results: The study included 159 patients who had 152 malignant lesions and 7 benign lesions. The malignant lesions included pancreatic cancers (n = 134), neuroendocrine neoplasms (n = 15), metastatic tumors (n = 2), and a solid pseudopapillary neoplasm (n = 1). The diagnostic accuracy of EUS-FNB (combining histology and cytology) was 98.7%. However, the histopathological diagnosis was only confirmed for 64.3% of small lesions (<10 mm), relative to 97.2% for larger lesions. Multivariate analysis also revealed that lesion size of <10 mm predicted a less accurate histopathological diagnosis (odds ratio: 6.97, 95% confidence interval: 1.02–47.67; p = 0.041). Further analyses revealed a failed histological diagnosis in 4 patients with lesions of <5 mm in size and accurate diagnoses in 9 out of 10 patients with lesions of 5–10 mm in size. Conclusions: The diagnostic accuracy for small lesions (<10 mm), especially for lesions of <5 mm, based on histological examination alone, was significantly lower than that for others (>10 mm). Furthermore, multivariate analysis revealed that only lesion size was an independent predictor of histopathological diagnosis accuracy.

Diagnostic yield of endoscopic ultrasound-guided tissue acquisition for small solid pancreatic lesions.

Background and study aims Endoscopic ultrasound (EUS)-guided tissue acquisition is sometimes required to diagnose small solid pancreatic lesions. The aim of this study was to evaluate the diagnostic yield of EUS-guided tissue acquisition for small solid pancreatic lesions and the differences in diagnostic yield among different needles. Patients and method We retrospectively analyzed consecutive patients who had undergone EUS-guided tissue acquisition for solid pancreatic lesions less than 2 cm between November 2012 and June 2019. Three types of needles were evaluated in this study: a 22-gauge fine-needle aspiration (FNA) Lancet needle, a 20-gauge fine-needle biopsy (FNB) Menghini needle with a lateral forward bevel, and a 22-gauge FNB Franseen needle. We evaluated the diagnostic yield and safety of the procedure using these needles. Results We analyzed 160 patients with 163 lesions. The overall sensitivity, specificity, and accuracy were 92.0 %, 100 %, and 92.6 %, respectively. In the histological plus cytological diagnosis, accuracies of the Lancet, Menghini, and Franseen needles were 92.7 %, 97.0 %, and 85.7 %, respectively ( P = 0.10). In the histological diagnosis alone, the negative predictive values (NPVs) of the Lancet, Menghini, and Franseen needles were 13.3 %, 53.3 %, and 27.3 %, respectively ( P = 0.08). Adverse events occurred in four cases (2.5 %): one postprocedural bleeding, two cases of pancreatitis, and one pancreatic abscess. Conclusions EUS-guided tissue acquisition for small solid pancreatic lesions has a high diagnostic yield and safety. This study suggested a difference in the diagnostic yield of each needle for small solid pancreatic lesions.

Endoscopic Ultrasound for Early Diagnosis of Pancreatic Cancer.

Detection of small pancreatic cancers, which have a better prognosis than large cancers, is needed to reduce high mortality rates. Endoscopic ultrasound (EUS) is the most sensitive imaging modality for detecting pancreatic lesions. The high resolution of EUS makes it particularly useful for detecting small pancreatic lesions that may be missed by other imaging modalities. Therefore, EUS should be performed in patients with obstructive jaundice in whom computed tomography (CT) or magnetic resonance imaging (MRI) does not identify a definite pancreatic lesion. Interest in the use of EUS for screening individuals at high risk of pancreatic cancer, including those with intraductal papillary mucinous neoplasms (IPMNs) and familial pancreatic cancer is growing. Contrast-enhanced EUS can facilitate differential diagnosis of small solid pancreatic lesions as well as malignant cystic lesions. In addition, EUS-guided fine needle aspiration can provide samples of small pancreatic lesions. Thus, EUS and EUS-related techniques are essential for early diagnosis of pancreatic cancer.

Elastography of the Pancreas, Current View.

Ultrasound elastography (USE) of the pancreas allows pancreatic tissue stiffness assessment by virtual palpation. Two main types of USE are used. For the pancreas strain elastography applying by endoscopic ultrasound has been established for the characterisation of small solid pancreatic lesions (SPL). In larger SPL >30 mm the results are less convincing mainly due to the heterogenicity of the lesions but also by concomitant changes of the surrounding pancreatic parenchyma. The current role of shear wave elastography has to be determined. This article reviews the current use of elastography of the pancreas.

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Andre Ignee et al. Endoscopic ultrasound elastography of small solid pancreatic lesions: a multicenter study

Endoscopic ultrasound elastography of small solid pancreatic lesions: a multicenter study.

The prevalence of malignancy in patients with small solid pancreatic lesions is low; however, early diagnosis is crucial for successful treatment of these cases. Therefore, a method to reliably distinguish between benign and malignant small solid pancreatic lesions would be highly desirable. We investigated the role of endoscopic ultrasound (EUS) elastography in this setting. Patients with solid pancreatic lesions ≤ 15 mm in size and a definite diagnosis were included. Lesion stiffness relative to the surrounding pancreatic parenchyma, as qualitatively assessed and documented at the time of EUS elastography, was retrospectively compared with the final diagnosis obtained by fine-needle aspiration/biopsy or surgical resection. 218 patients were analyzed. The average size of the lesions was 11 ± 3 mm; 23 % were ductal adenocarcinoma, 52 % neuroendocrine tumors, 8 % metastases, and 17 % other entities; 66 % of the lesions were benign. On elastography, 50 % of lesions were stiffer than the surrounding pancreatic parenchyma (stiff lesions) and 50 % were less stiff or of similar stiffness (soft lesions). High stiffness of the lesion had a sensitivity of 84 % (95 % confidence interval 73 % - 91 %), specificity of 67 % (58 % - 74 %), positive predictive value (PPV) of 56 % (50 % - 62 %), and negative predictive value (NPV) of 89 % (83 % - 93 %) for the diagnosis of malignancy. For the diagnosis of pancreatic ductal adenocarcinoma, the sensitivity, specificity, PPV, and NPV were 96 % (87 % - 100 %), 64 % (56 % - 71 %), 45 % (40 % - 50 %), and 98 % (93 % - 100 %), respectively. In patients with small solid pancreatic lesions, EUS elastography can rule out malignancy with a high level of certainty if the lesion appears soft. A stiff lesion can be either benign or malignant.

Diagnostic yield of EUS-FNA of small (≤15 mm) solid pancreatic lesions using a 25-gauge needle

BackgroundEarly detection of small solid pancreatic lesions is increasingly common. To date, few and contradictory data have been published about the relationship between lesion size and endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) diagnostic yield. The aim of this study was to assess the relation between the size of solid pancreatic lesions and the diagnostic yield of EUS-FNA using a 25-gauge needle in a center without available rapid on-site evaluation. MethodsIn the retrospective cohort study, we selected patients who underwent EUS-FNA for solid pancreatic lesions with a 25-gauge needle from October 2014 to October 2015. Patients were divided into three groups (≤15 mm, 16–25 mm and >25 mm), and the outcomes were compared. ResultsWe analyzed 163 patients. Overall adequacy, sensitivity, specificity and accuracy were 85.2%, 81.8%, 93.7%, and 80.4%, respectively. When stratified by size, the sensitivity and accuracy correlated with size (P = 0.016 and P = 0.042, respectively). Multivariate analysis showed that lesion size was the only independent factor (P = 0.019, OR = 4.76) affecting accuracy. The role of size as an independent factor affecting accuracy was confirmed in a separate multivariate analysis, where size was included in the model as a covariate (P = 0.018, OR = 1.08). ConclusionOur study demonstrates that, in the absence of rapid on-site evaluation, mass size affects the accuracy of EUS-FNA of solid pancreatic lesions.

Contrast-enhanced ultrasound of small focal solid pancreatic lesions: A must!

Contrast-enhanced ultrasound of small focal solid pancreatic lesions: A must!

Differential diagnosis of small solid pancreatic lesions.

Pancreatic ductal adenocarcinoma (PDAC) is typically diagnosed at a late stage. Little is known about the incidental finding of early-stage PDAC. The aim of the current study was to determine the etiology of small solid pancreatic lesions (≤15mm) to optimize clinical management. Inclusion criterion for the retrospective study analysis was the incidental finding of primarily undetermined small solid pancreatic lesions≤15mm in 394 asymptomatic patients. Final diagnoses were based on histology or cytology obtained by imaging-guided biopsy (and at least 12-month follow-up) and/or surgery. Contrast-enhanced US or contrast-enhanced EUS was performed in 219 patients. The final diagnoses of 394 patients were as follows: 146 PDACs, 156 neuroendocrine tumors, 28 metastases into the pancreas from other primary sites, and 64 various other etiologies. Contrast-enhanced US allowed differential diagnosis of PDAC and non-PDAC in 189 of 219 patients (86%). Approximately 40% of patients with small solid pancreatic lesions had very early stage PDAC. Approximately 60% of small solid pancreatic lesions≤15mm are not PDAC and, therefore, do not require radical surgery. Without preoperative diagnosis, an unacceptably large proportion of patients would be exposed to radical surgery with significant morbidity and mortality.

Comparison of Multidetector CT and Gadobutrol-Enhanced MR Imaging for Evaluation of Small, Solid Pancreatic Lesions.

ObjectiveTo compare multidetector computed tomography (MDCT) and MRI for lesion conspicuity, as well as the detection and characterization of small solid pancreatic lesions (SPLs).Materials and Methods193 patients with small SPLs (< 3 cm) and 52 patients with normal pancreas who underwent both multiphasic MDCT and gadobutrol-enhanced MRI were included in our study. Two radiologists blinded to the pathologic diagnoses independently reviewed those images, and determined the detection of "SPL per se" and "SPL in consideration of secondary features", the lesion conspicuity, the probability of pancreatic ductal adenocarcinoma (PDAC), and the most likely specific diagnosis.ResultsThe sensitivity of MRI for "detection of SPL per se" was significantly higher than that of CT in both reviewers: 92.7% (179/193) and 97.9% (189/193), respectively, for reviewer 1 (p = 0.031) and 90.7% (175/193) and 99.5% (192/193), respectively, for reviewer 2 (p < 0.001). In addition, MRI provided better lesion conspicuity than MDCT for both reviewers (p < 0.001). However, CT and MRI did not show significant difference in sensitivity for "detection of SPL in consideration of secondary features", specificity for SPL detection, and differentiation of PDAC vs. non-PDAC (p > 0.05). The accuracies of CT and MRI for making a specific diagnosis were as follows: 85.7% (210/245) vs. 86.9% (213/245), respectively, for reviewer 1 (p = 0.736), and 91.8% (225/245) vs. 93.5% (229/245), respectively, for reviewer 2 (p = 0.454).ConclusionMRI showed better lesion conspicuity than MDCT, but did not show significantly different diagnostic performance compared with MDCT for detecting and characterizing small SPLs.

Endoscopic ultrasound-guided fine-needle biopsy of small solid pancreatic lesions using a 22-gauge needle with side fenestration.

Early detection of small pancreatic cancer is important because expected survival is markedly better for tumors ≤ 2 cm. A new endoscopic ultrasound-(EUS) guided biopsy needle with side fenestration has been recently developed to enable fine-needle biopsy (FNB) under EUS guidance. The aim of this study was to evaluate the outcome of EUS-FNB using a 22-gauge ProCore needle in solid pancreatic lesions ≤ 2 cm, in terms of diagnostic accuracy and yield. From January 2011 to December 2012, all consecutive EUS-guided tissue sampling of small pancreatic lesions (≤ 2 cm) were performed using 22-gauge ProCore needles; the data of these patients were analyzed retrospectively. Sixty-eight patients with a mean age of 65.7 years were included. The mean lesion size was 16.5 mm (range 5-20). None of the patients developed complications. On pathological examination, the tissue retrieved was judged adequate in 58 out of 68 cases (85.3 %) and the presence of a tissue core was recorded in 36 out of 68 cases (52.9 %). The overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 80, 100, 100, 40, and 82 %, respectively. Our results suggested that EUS-FNB of small pancreatic lesions using a 22-gauge ProCore needle is effective and safe, and supports our hypothesis that EUS-FNB is highly useful in establishing the nature of small pancreatic lesions.

Mo1452 Echo-Enhanced Endoscopic Ultrasound for the Differentiation of Small Solid Pancreatic Lesions

small solid, non-cystic pancreatic lesions are found more and more frequently with high resolution endoscopic ultrasound. Various attempts were made to determine the clinical benefit of endoscopic ultrasound in the differentiation of pancreatic tumors using color doppler techniques and echo-enhanced percutaneous ultrasound by our working group. In this small study we examined only patients with small solid lesions of the panceas (max. diameter 20 mm) using a special software tool with echo-enhanced endoscopic ultrasound (low-MI scanning, subtraction of the grayscale background, visualization of the perfusion pattern).

Diagnostic impact of 18F-FDG PET–CT evaluating solid pancreatic lesions versus endosonography, endoscopic retrograde cholangio-pancreatography with intraductal ultrasonography and abdominal ultrasound

This prospective single-centre phase II trial assessed the diagnostic impact of (18)F-FDG PET-CT in the evaluation of solid pancreatic lesions (phi >or= 10 mm) compared to endosonography (EUS), endoscopic retrograde cholangio-pancreatography (ERCP) with intraductal ultrasound (IDUS), abdominal ultrasound (US) and histopathological reference. Forty-six patients (32 men/14 women, phi 61.7 years) with suspected pancreatic neoplasms underwent PET-CT with contrast-enhanced biphasic multi-detector CT of the upper abdomen followed by a diagnostic work-up with EUS, ERCP with IDUS and US within 3 weeks. PET-CT data sets were analysed by two expert readers in a consensus reading. Histology from surgery, biopsy/fine-needle aspiration and/or clinical follow-up >or=12 months served as standard of reference. Twenty-seven pancreatic malignancies were histopathologically proven; 19 patients had benign diseases: 36/46 lesions (78%) were detected in the head of the pancreas, 7/46 and 3/46 in the body and tail region, respectively. Sensitivity and specificity of PET-CT were 89% and 74%, respectively; positive predictive value (PPV) and negative predictive value (NPV) were 83% and 82%, respectively. Sensitivity (81-89%), specificity (74-88%), PPV (83-90%) and NPV (77-82%) achieved by EUS, ERCP and US were not significantly different. PET analysis revealed significantly higher maximum mean standardised uptake values (SUV(max) 6.5+/-4.6) in patients with pancreatic malignancy (benign lesions: SUV(max) 4.2+/-1.5; p<0.05). PET-CT revealed cervical lymphonodal metastasis from occult bronchogenic carcinoma and a tubular colon adenoma with intermediate dysplasia on polypectomy, respectively. (18)F-FDG PET-CT achieves a comparably high diagnostic impact evaluating small solid pancreatic lesions versus conventional reference imaging modalities. Additional clinical diagnoses are derived from concomitant whole-body PET-CT imaging.