Endoscopic ultrasound-guided tissue acquisition of solid mass lesions of the pancreas: A retrospective comparison study of fine-needle aspiration and fine-needle biopsy

Preliminary study on the ability of the machine learning models based on 18F-FDG PET/CT to differentiate between mass-forming pancreatic lymphoma and pancreatic carcinoma

PURPOSE

The objective of this study was to preliminarily assess the ability of metabolic parameters and radiomics derived from 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) to distinguish mass-forming pancreatic lymphoma from pancreatic carcinoma using machine learning.

METHODS

A total of 88 lesions from 86 patients diagnosed as mass-forming pancreatic lymphoma or pancreatic carcinoma were included and randomly divided into a training set and a validation set at a 4-to-1 ratio. The segmentation of regions of interest was performed using ITK-SNAP software, PET metabolic parameters and radiomics features were extracted using 3Dslicer and PYTHON. Following the selection of optimal metabolic parameters and radiomics features, Logistic regression (LR), support vector machine (SVM), and random forest (RF) models were constructed for PET metabolic parameters, CT radiomics, PET radiomics, and PET/CT radiomics. Model performance was assessed in terms of area under the curve (AUC), accuracy, sensitivity, and specificity in both the training and validation sets.

RESULTS

Strong discriminative ability observed in all models, with AUC values ranging from 0.727 to 0.978. The highest performance exhibited by the combined PET and CT radiomics features. AUC values for PET/CT radiomics models in the training set were LR 0.994, SVM 0.994, RF 0.989. In the validation set, AUC values were LR 0.909, SVM 0.883, RF 0.844.

CONCLUSION

Machine learning models utilizing the metabolic parameters and radiomics of 18F-FDG PET/CT show promise in distinguishing between pancreatic carcinoma and mass-forming pancreatic lymphoma. Further validation on a larger cohort is necessary before practical implementation in clinical settings.

Small biopsies for pancreatic lesions: Is there still room for fine needle aspiration?

Pancreatic carcinoma is an aggressive tumour with increasing incidence in both sexes worldwide. Early detection is, therefore, essential for patient management. A recent advancement involves the utilization of larger, thicker gauge needles, which enable the collection of core-type biopsies (FNB). Here, we investigated the role of fine needle aspiration and cytopathology in the diagnostic workflow of pancreatic lesions. A search query was designed to search for articles in the PubMed database comparing FNA and FNB for biopsy of pancreatic lesions, and detailed data were extracted from selected studies. Statistical analyses were performed using the R package meta version 6.2. Twenty-one studies made the final cut for data extraction. Overall, median age was 64.3 years (±6.1; 47.6-71.5), male: female proportion 53.9 (±11.3; 27.6-67.4), lesion size 3.1 cm (±0.5; 1.9-4.2 cm) and percentage of malignant cases 78.3% (±26.8; 2.1-100). FNA and FNB diagnostic yield was 85.8% (±10.3; 70.0-100.0) and 89.2% (±7.7; 70.0-98.6), respectively. Average accuracy was 89.5% (±11.7; 63.0-100.0) for FNA and 90.8% (±7.1; 77.0-100.0) for FNB. Adverse effects rate was 1.0% (±1.3; 0-4.3) for FNA and 2.2% (±4.4; 0-16.1) for FNB. None of the selected variables had a significant statistical difference between both methods. FNA and FNB perform similarly for diagnostic material acquisition in pancreatic lesions. The best outcome comes from the association of both techniques, emphasizing the value of combining cytological and histological morphology for the most accurate analysis.

Sensitivity of endoscopic ultrasound-guided fine-needle aspiration cytology and biopsy for a diagnosis of pancreatic ductal adenocarcinoma: A comparative analysis

The utility of endoscopic ultrasound fine-needle aspiration cytology (EUS-FNAC) or endoscopic ultrasound fine-needle aspiration biopsy (EUS-FNAB) for diagnosis of small and large pancreatic ductal adenocarcinomas (PDACs) remains in question. We addressed this by analyzing 97 definitively diagnosed cases of PDAC, for which both EUS-FNAC and EUS-FNAB had been performed. We subclassified the 97 solid masses into small (n = 35) or large (n = 62) according to the maximum tumor diameter (<24 mm or ≥24 mm) and compared the diagnostic sensitivity (truly positive rate) of EUS-FNAC and of EUS-FNAB for small and large masses. Diagnostic sensitivity of EUS-FNAC did not differ between large and small masses (79.0% vs. 60.0%; p = 0.0763). However, the diagnostic sensitivity of EUS-FNAB was significantly higher for large masses (85.5% vs. 62.9%; p = 0.0213). Accurate EUS-FNAC-based diagnosis appeared to depend on the degree of cytological atypia of cancer cells, which was not associated with quantity of cancer cells. The accuracy of EUS-FNAB-based diagnosis appeared to depend on cancer cell viability in large masses and cancer volume in small masses. Based on the advantages or disadvantages in each modality, both modalities play an important role in the qualitative diagnosis of PDAC as a complementary procedure.

Revisiting the cytologic features of autoimmune pancreatitis: An institutional experience

BACKGROUND

Autoimmune pancreatitis (AIP) is a known mimicker of pancreatic ductal adenocarcinoma both clinically and radiologically. In this study, the authors present their institutional experience in diagnosing AIP on cytology and correlate results with the histologic findings.

METHODS

A 14-year computerized search for patients who had histologically confirmed AIP with concurrent or prior cytology was performed. Clinical data, cytology findings, and surgical pathology results were reviewed for analysis.

RESULTS

Eighteen patients were identified. The patients showed a male predominance, with a mean age of 59 years. Jaundice, weight loss, and abdominal pain were the most common clinical presentation. Five of 12 patients who were tested for serum immunoglobulin G4 had elevated levels. Cytologic findings of 16 cases that were available for review showed markedly inflamed fibrous stroma (54%) and cytologic atypia (50%). The final cytologic diagnoses were suspicious for adenocarcinoma (n = 1), atypical (n = 8), and benign/negative (n = 9). The corresponding surgical pathology diagnoses were classified as type 1 (n = 10), type 2 (n = 6), and AIP, not otherwise specified (n = 2). All type 2 AIP cases had at least atypical cytologic diagnoses, with one called suspicious for adenocarcinoma and another called adenocarcinoma at the time of rapid on-site evaluation. In contrast, eight of 10 type 1 AIP cases were negative/benign, and two of 10 were atypical. In these two atypical cases, the possibility of AIP was raised because of the presence of inflamed stroma.

CONCLUSION

AIP is a pitfall in cytology because moderate-to-marked atypia can be present, especially in type 2 AIP. Because atypia can be severe, the presence of cellular fibrous stroma with lymphocytic stromal infiltrates and the integration of serum immunoglobulin G4 levels could be helpful in avoiding diagnostic overcall in AIP.

Diagnostic performance of endoscopic ultrasound-guided tissue acquisition by EUS-FNA versus EUS-FNB for solid pancreatic mass without ROSE: a retrospective study

BACKGROUND

Endoscopic ultrasound-guided tissue acquisition (EUS-TA) is an established diagnostic procedure for solid pancreatic mass. However, the diagnostic yield between fine-needle aspiration (FNA) and fine-needle biopsy (FNB) remains unclear. We aimed to evaluate and compare the diagnostic yields between FNA and FNB using conventional FNA and Franseen needles of the same size 22-gauge needle, in patients with solid pancreatic mass who underwent EUS-TA without rapid onsite cytopathology evaluation (ROSE).

METHODS

All cases of EUS-TA by FNA or FNB for solid pancreatic mass between January 2017 and October 2020 in a single-centre university hospital were retrospectively reviewed. All procedures were performed without an onsite cytologist. Before the endoscopist finished the procedure, macroscopic onsite evaluation (MOSE) was confirmed. The diagnostic yield and the average number of needle passes between FNB and FNA were then compared.

RESULTS

A total of 151 patients (FNA, n = 77; FNB, n = 74) with solid pancreatic mass detected by cross-sectional imaging underwent EUS-TA. The mean age was 62.3 ± 12.8 years, with 88 (58.3%) males. Age, sex, mass location, tumour size and disease stage from imaging were not significantly different between the two groups. The diagnostic performance was higher in EUS-FNB (94.6%) than in EUS-FNA (89.6%). The mean number of needle passes was clearly fewer in FNB than in FNA (2.8 vs. 3.8, p < 0.001). The total procedure time was shorter in FNB (34.7 min) than in FNA (41 min). The adverse event rate between FNB and FNA was not significantly different.

CONCLUSIONS

The diagnostic yield of solid pancreatic mass was higher in FNB using the Franseen needle than in FNA using the conventional FNA needle in a centre where ROSE is unavailable, without serious adverse event. In addition, FNB had fewer needle passes and shorter total procedure time.

Accuracy and clinical outcomes of pancreatic EUS-guided fine-needle biopsy in a consecutive series of 852 specimens

Background and Objectives:

Pancreatic EUS-guided fine needle biopsy (EUS-FNB) is increasingly used. Accuracy of EUS-FNB, particularly for benign diseases, utility of additional EUS-FNB if malignancy is suspected but initial diagnosis is inconclusive, and complication rate are not fully elucidated. We evaluated operating characteristics of EUS-FNB overall and for different diagnostic categories, value of additional EUS-FNB if malignancy is suspected but initial diagnosis is inconclusive, and frequency and type of complications.

Methods:

A retrospective tertiary single-center study including 852 consecutive pancreatic SharkCore EUS-FNBs from 723 patients between 2015 and 2020. EUS-FNB diagnoses were applied according to Papanicolaou Society's system and each category was further subcategorized.

Results:

Sufficient tissue cylinders for a histologic diagnosis were obtained in 93.4% (796/852). Accuracy was overall, for malignant, and benign entities 85.6% (confidence interval [CI]: 83.2%–87.9%), 88.3% (CI: 85.9%–90.4%), and 94% (CI: 92.2%–95.5%). Sensitivity and accuracy of EUS-FNB for autoimmune pancreatitis (AIP) (n = 15) was 83.3% (CI: 58.6%–96.4%) and 99.2% (CI: 98.3%–99.7%). Of patients in whom malignancy was suspected but initial EUS-FNB diagnosis was inconclusive, 7.3% (53/723) underwent one or two additional EUS-FNBs, and in 54.7% (29/53) of these, a malignant diagnosis was established. The frequency of hospitalization following EUS-FNB was 4.7%, with 0.2% (n = 2) incidents needing active intervention.

Conclusions:

We found a high accuracy of pancreatic EUS-FNB across all diagnostic categories including rare entities, such as AIP. In patients with a clinical suspicion of malignancy, additional EUS-FNB resulted in a conclusive diagnosis in more than half of cases. Complications necessitate hospitalization in almost 5%, but the majority are self-limiting.

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.

Evaluating Pancreatic and Biliary Neoplasms with Small Biopsy-Based Next Generation Sequencing (NGS): Doing More with Less

Simple Summary

Pancreatic cancer and cholangiocarcinoma are aggressive diseases mostly diagnosed at an advanced and inoperable stage. This review presents the value of next-generation sequencing (NGS) when performed on small biopsies—including fine-needle aspiration/biopsy samples, brushings, pancreatic juice and bile, and also blood—in the field of pancreatobiliary neoplasia. NGS could guide physicians while evaluating pancreatic solid and cystic lesions or suspicious biliary strictures, performing surveillance in high-risk individuals, or monitoring the disease and assessing prognosis in already diagnosed cancer patients. Evidence suggests that NGS performed on small biopsies is a robust tool for the diagnosis and pre-operative risk stratification of pancreatic and biliary lesions, whereas it also carries significant prognostic and therapeutic value. However, effective standardization of the pre-analytical and analytical assay parameters used for each clinical scenario is needed to fully implement NGS into routine practice and provide more personalized management in patients with suspected or established pancreatobiliary neoplasia.

Abstract

Pancreatic cancer and cholangiocarcinoma are lethal diseases mainly diagnosed at an inoperable stage. As pancreatobiliary surgical specimens are often unavailable for further molecular testing, this review aimed to highlight the diagnostic, prognostic, and therapeutic impact of next-generation sequencing (NGS) performed on distinct small biopsies, including endoscopic ultrasound fine-needle aspirations and biopsies of pancreatic solid and cystic lesions, biliary duct brushings, and also “liquid biopsies” such as the pancreatic juice, bile, and blood. NGS could clarify indeterminate pancreatic lesions or biliary strictures, for instance by identifying TP53 or SMAD4 mutations indicating high-grade dysplasia or cancer. It could also stratify pancreatic cystic lesions, by distinguishing mucinous from non-mucinous cysts and identifying high-risk cysts that should be excised in surgically fit patients, whereas the combination of cytology, elevated cystic CEA levels and NGS could improve the overall diagnostic accuracy. When NGS is performed on the pancreatic juice, it could stratify high-risk patients under surveillance. On the plasma, it could dynamically monitor the disease course and response to therapy. Notably, the circulating tumor DNA (ctDNA) levels have been associated with staging, grading, and survival. Lastly, NGS has shown potential in identifying potentially actionable molecular alterations. In conclusion, NGS applied on small biopsies could carry significant diagnostic, prognostic, and therapeutic value.

Adequacy evaluation and use of pancreatic adenocarcinoma specimens for next-generation sequencing acquired by endoscopic ultrasound-guided FNA and FNB

BACKGROUND

Endoscopic ultrasound-guided tissue acquisition (EUS-TA), especially endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), is the mainstay of tissue acquisition for the diagnosis of pancreatic ductal adenocarcinoma (PDAC). Recently, endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) using flexible biopsy needles has been used for patients with PDAC in an effort to increase diagnostic yields and biomarker testing. However, the role of EUS-TA in biomarker testing for personalized therapy or precise chemotherapy for PDAC is not well established.

METHODS

PDAC cases with specimens acquired through concurrent EUS-FNA and EUS-FNB were identified retrospectively. Smears were prepared from EUS-FNA sampling, and cell blocks (CBs) were prepared from EUS-FNB sampling. Rapid onsite evaluation was conducted for all cases for diagnostic adequacy. The adequacy for biomarker testing, including next-generation sequencing (NGS) and immunohistochemistry (IHC) assays, was evaluated, and cases with smears and CBs adequate for NGS were processed for targeted NGS.

RESULTS

There were 26 PDAC cases concurrently sampled by EUS-FNA and EUS-FNB. EUS-FNA smears for all 26 cases and EUS-FNB CBs for 20 cases (77%) were diagnostic for PDAC. Twenty-one smears (81%) and 11 CBs (42%) were adequate for NGS. Nine cases with both smears and CBs adequate for NGS underwent NGS, which identified clinically significant gene mutation variants, including KRAS, TP53, and SMAD4 mutations.

CONCLUSIONS

Both EUS-FNA and EUS-FNB can provide optimal material for targeted NGS for PDACs. In PDAC cases subjected to concurrent EUS-FNA and EUS-FNB, EUS-FNA specimens had greater diagnostic yields and more adequate material for NGS than EUS-FNB specimens, whereas EUS-FNB was more suitable for IHC-based biomarker testing.

[Preoperative diagnostics of pancreatic neoplasms]

While patients with clinico-radiologically diagnosed resectable pancreatic cancer usually undergo surgery without preoperative cytological or histopathological diagnostics, patients with inoperable tumors or ambiguous findings in imaging often undergo EUS-FNA or EUS-FNB (endoscopic ultrasound-guided fine-needle aspiration or endoscopic ultrasound-guided fine-needle biopsy). In many cases, this concerns pancreatic cystic lesions, which can range from benign inflammatory pseudocysts to invasive pancreatic cancer emerging from intraductal papillary mucinous neoplasms (IPMNs) or mucinous cystic neoplasms (MCNs). However, the evaluation of EUS-FNA material can be especially hampered by contamination with gastric or enteric cells or mucin, degenerative changes, or low or even no cellularity of the sample. Next-generation-sequencing-based molecular analyses, especially of cystic lesions, can significantly increase the accuracy of EUS-FNA diagnostics of the pancreas. Interpretation of morphological and molecular data considering each case's clinico-radiological context is crucial. While reliable molecular markers for the detection of mucinous and specific nonmucinous pancreatic neoplasms already exist, establishing valid markers for the detection of high-grade lesions is an urgent future goal.

Comparison of EUS-guided conventional smear and liquid-based cytology in pancreatic lesions: A systematic review and meta-analysis

Background and study aims  Endoscopic ultrasound (EUS)-guided fine-needle aspiration (EUS-FNA) has limitations of inadequate sampling and false-negative results for malignancy. It has been performed using conventional smear (CS) cytology with rapid on-site evaluation (ROSE) with reasonable diagnostic accuracy. An alternative to ROSE is liquid-based cytology (LBC). Commonly used LBC techniques include precipitation-based (SurePath™) and filtration-based (ThinPrep ^® , CellPrep ^® ). Data regarding the diagnostic efficacy of LBC compared with CS are limited. Methods  Multiple databases were searched through March 2020 to identify studies reporting diagnostic yield of EUS-guided CS and LBC in pancreatic lesions. Pooled diagnostic odds and rates of performance for the cytologic diagnoses of benign, suspicious, and malignant lesions were calculated. Diagnostic efficacy was evaluated by pooled rates of accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Results  Nine studies with a total of 1308 patients were included in our final analysis. Pooled diagnostic odds of CS cytology were 1.69 (CI 1.02-2.79) and 0.39 (CI 0.19-0.8) for malignant lesions when compared to filtration-based and precipitation-based LBC techniques, respectively. For CS, precipitation-based and filtration-based LBC, pooled diagnostic accuracy was 79.7 %, 85.2 %, 77.3 %, sensitivity was 79.2 %, 83.6 %, 68.3 %, and specificity was 99.4 %, 99.5 %, 99.5 %, respectively. Conclusions  The precipitation-based LBC technique (SurePath™) had superior diagnostic odds for malignant pancreatic lesions compared with CS cytology in the absence of ROSE. It showed superior accuracy and sensitivity, but comparable specificity and PPV. Diagnostic odds of CS cytology in the absence of ROSE were superior to the filtration-based LBC technique (ThinPrep ^® , Cellprep ^® ) for diagnosing malignant pancreatic lesions.