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

OBJECTIVES: Endoscopic ultrasound-guided tissue acquisition (EUS-TA) is used for pathological diagnosis and obtaining samples for molecular testing, facilitating the initiation of targeted therapies in patients with pancreatic cancer. However, samples obtained via EUS-TA are often insufficient, requiring more efforts to improve sampling adequacy for molecular testing. Therefore, this study investigated the use of oil blotting paper for formalin fixation of samples obtained via EUS-TA. METHODS: This prospective study enrolled 42 patients who underwent EUS-TA for pancreatic cancer between September 2020 and February 2022 at the Osaka International Cancer Institute. After a portion of each sample obtained via EUS-TA was separated for routine histological evaluation, the residual samples were divided into filter paper and oil blotting paper groups for analysis. Accordingly, filter paper and oil blotting paper were used for the formalin fixation process. The total tissue, nuclear, and cytoplasm areas of each sample were quantitatively evaluated using virtual slides, and the specimen volume and histological diagnosis of each sample were evaluated by an expert pathologist. RESULTS: All cases were cytologically diagnosed as adenocarcinoma. The area ratios of the total tissue, nuclear, and cytoplasmic portions were significantly larger in the oil blotting paper group than in the filter paper group. The frequency of cases with large amount of tumor cells was significantly higher in the oil blotting paper group (33.3%) than in the filter paper group (11.9%) (p = 0.035). CONCLUSIONS: Oil blotting paper can increase the sample volume obtained via EUS-TA on glass slides and improve sampling adequacy for molecular testing.

Clinical values of different specimen preparation methods for the diagnosis of lung cancer by EBUS-TBNA.

BACKGROUND AND OBJECTIVE: EBUS-TBNA has emerged as an important minimally invasive procedure for the diagnosis and staging of lung cancer. Our objective was to evaluate the effect of different specimen preparation from aspirates on the diagnosis of lung cancer. METHODS: 181 consecutive patients with known or suspected lung cancer accompanied by hilar / mediastinal lymphadenopathy underwent EBUS-TBNA from January 2019 to December 2022. Specimens obtained by EBUS-TBNA were processed by three methods: Traditional smear cytology of aspirates (TSC), liquid-based cytology of aspirates (LBC) and histopathology of core biopsies. RESULTS: EBUS-TBNA was performed in 181 patients on 213 lymph nodes, the total positive rate of the combination of three specimen preparation methods was 80.7%. The diagnostic positive rate of histopathology was 72.3%, TSC was 68.1%, and LBC was 65.3%, no significant differences was observed (p = 0.29); however, statistically significant difference was noted between the combination of three preparation methods and any single specimen preparation methods (p = 0.002). The diagnostic sensitivity of histopathology combined with TSC and histopathology combined with LBC were 96.5 and 94.8%, the specificity was 95.0% and 97.5%, the PPV was 98.8% and 99.4%, the NPV was 86.4% and 81.2%, the diagnostic accuracy was 96.2% and 95.3%, respectively; The sensitivity and accuracy of above methods were higher than that of single specimen preparation, but lower than that of combination of three preparation methods. CONCLUSION: When EBUS-TBNA is used for the diagnosis and staging of lung cancer, histopathology combined with TSC can achieve enough diagnostic efficiency and better cost-effectiveness.

Utility of bronchoscopically obtained frozen cytology pellets for next-generation sequencing.

BACKGROUND: Next-generation sequencing (NGS) is essential for lung cancer treatment. It is important to collect sufficient tissue specimens, but sometimes we cannot obtain large enough samples for NGS analysis. We investigated the yield of NGS analysis by frozen cytology pellets using an Oncomine Comprehensive Assay or Oncomine Precision Assay. METHODS: We retrospectively enrolled patients with lung cancer who underwent bronchoscopy at Kobe University Hospital and were enrolled in the Lung Cancer Genomic Screening Project for Individualized Medicine. We investigated the amount of extracted DNA and RNA and determined the NGS success rates. We also compared the amount of DNA and RNA by bronchoscopy methods. To create the frozen cytology pellets, we first effectively collected the cells and then quickly centrifuged and cryopreserved them. RESULTS: A total of 132 patients were enrolled in this study between May 2016 and December 2022; of them, 75 were subjected to frozen cytology pellet examinations and 57 were subjected to frozen tissue examinations. The amount of DNA and RNA obtained by frozen cytology pellets was nearly equivalent to frozen tissues. Frozen cytology pellets collected by endobronchial ultrasound-guided transbronchial needle aspiration yielded significantly more DNA than those collected by transbronchial biopsy methods. (P < 0.01) In RNA content, cytology pellets were not inferior to frozen tissue. The success rate of NGS analysis with frozen cytology pellet specimens was comparable to the success rate of NGS analysis with frozen tissue specimens. CONCLUSIONS: Our study showed that frozen cytology pellets may have equivalent diagnostic value to frozen tissue for NGS analyses. Bronchial cytology specimens are usually used only for cytology, but NGS analysis is possible if enough cells are collected to create pellet specimens. In particular, the frozen cytology pellets obtained by endobronchial ultrasound-guided transbronchial needle aspiration yielded sufficient amounts of DNA. TRIAL REGISTRATION: This was registered with the University Medical Hospital Information Network in Japan (UMINCTR registration no. UMIN000052050).

Adenocarcinoma originating in the anterior mediastinum diagnosed by endobronchial ultrasound-guided transbronchial cryobiopsy: a case report.

BACKGROUND: Endobronchial ultrasound-guided transbronchial cryobiopsy (EBUS-cryobiopsy) is advantageous for collecting larger specimens with minimal crushing; however, it has not been widely used for mediastinal tumors. CASE PRESENTATION: A 73-year-old woman with a history of left breast cancer underwent surgery followed by radiotherapy. Computed tomography showed a mass in the anterior mediastinum that was in extensive contact with the sternum on the ventral side and partly with the trachea on the dorsal side. Two computed tomography-guided needle biopsies (CTNBs) were performed on the mass; however, a definitive diagnosis was not made because of severe crush artifacts. Subsequently, we performed EBUS-cryobiopsy and safely obtained sufficient specimen volume with minimal crushing. The histopathological diagnosis was adenocarcinoma, with immunobiological features distinct from those of previous breast cancers. Her overall diagnosis was a rare tumor originating in the anterior mediastinum. CONCLUSIONS: EBUS-cryobiopsy can be safely performed in narrow areas surrounded by major blood vessels, and the obtained specimens may be superior to CTNBs for histopathological diagnosis.

Endoscopic ultrasound for the diagnosis and treatment of primary hepatocellular carcinoma.

Chronic liver disease has emerged as a significant global concern, with primary hepatocellular carcinoma (HCC) representing a critical consequence of this disease. However, early detection of HCC remains challenging in clinical practice. Recently, there has been a growing interest in applying endoscopic ultrasound (EUS) as a diagnostic tool for gastrointestinal diseases. Nevertheless, using EUS to diagnose and treat HCC is uncommon. In this review we described the diagnostic and therapeutic applications of EUS in primary HCC and evaluated its clinical significance. The diagnostic procedures primarily involve EUS-guided fine-needle biopsy or aspiration, assessment of metastatic lymph nodes and portal vein thrombosis, portal pressure monitoring, and portal vein blood collection. Treatment mainly includes EUS-guided tumor ablation, brachytherapy, injectable chemotherapy, and managing variceal hemorrhage related to portal hypertension.

Retrospective application of WHO reporting system for lung cytopathology with assessment of risk of malignancy.

INTRODUCTION: The recently introduced World Health Organization (WHO) Reporting System for Lung Cytopathology presents 5 diagnostic categories with corresponding risk of malignancy (ROM) and management protocols. This study uses the system to categorize our institutional respiratory tract cytology specimens, evaluating ROM and diagnostic accuracy for each category. MATERIALS AND METHODS: In a retrospective analysis (May 2020 to August 2021), the following respiratory cytology specimens were classified based on the WHO categories: bronchoalveolar lavage (BAL), bronchial wash/bronchial brushings (BB/BW), endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), fine-needle aspiration cytology (FNAC), sputum, biopsy imprint (BI), and endotracheal wash. Exclusions comprised pleural effusions and EBUS-TBNA from mediastinal and hilar lymph nodes. Correlation of cytologic and histopathologic diagnoses was performed to assess ROM collectively and individually. RESULTS: A total of 1518 respiratory samples (BAL [968], BW/BB [380], EBUS-TBNA [42], FNAC [32], sputum [80], BI [11] and endotracheal wash [5]) of 1410 patients were screened, of which 522 cases (34.3%) had histopathologic correlation. One hundred forty-one cases (9.3%) were Insufficient/Inadequate/Non-Diagnostic (ND), 1221 (80.4%) were Benign (B), 3 (0.2%) were Atypical (A), 32 (2.1%) were Suspicious for malignancy (SM) and 121 (8.0%) were Malignant (M). The estimated ROM for each category was 49.2% for ND, 13.3% for B, 66.6% for A, 81.5% for SM and 92.7% for M. FNAC and EBUS-TBNA exhibited the highest sensitivity (100%) compared with BW/BB (66.3%). Specificity ranged from 96.8% to 100% across the samples, while diagnostic accuracy varied from 58.8% to 100%. CONCLUSIONS: Application of the WHO reporting system enhances standardized terminology, aiding clinicians in informed decision-making and improving patient care through accurate risk assessment of malignancy.

Liquid biopsy of wash samples obtained via endoscopic ultrasound-guided fine-needle biopsy: Comparison with liquid biopsy of plasma in pancreatic cancer.

OBJECTIVES: Pancreatic cancer (PC) has a poor prognosis and limited treatment options. Liquid biopsy, which analyzes circulating tumor DNA (ctDNA) in blood, holds promise for precision medicine; however, low ctDNA detection rates pose challenges. This study aimed to investigate the utility of wash samples obtained via endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) as a liquid biopsy for PC. METHODS: A total of 166 samples (42 formalin-fixed paraffin-embedded [FFPE] tissues, 80 wash samples, and 44 plasma samples) were collected from 48 patients with PC for genomic analysis. DNA was extracted and quantified, and 60 significantly mutated genes were sequenced. The genomic profiles of FFPE tissues, wash samples, and plasma samples were compared. Finally, the ability to detect druggable mutations in 80 wash samples and 44 plasma samples was investigated. RESULTS: The amount of DNA was significantly lower in plasma samples than in wash samples. Genomic analysis revealed a higher detection rate of oncogenic mutations in FFPE tissues (98%) and wash samples (96%) than in plasma samples (18%) and a comparable detection rate in FFPE tissues and wash samples. Tumor-derived oncogenic mutations were detected more frequently in wash samples than in plasma samples. Furthermore, the oncogenic mutations detection rate remained high in wash samples at all PC stages but low in plasma samples even at advanced PC stages. Using wash samples was more sensitive than plasma samples for identifying oncogenic and druggable mutations. CONCLUSIONS: The wash sample obtained via EUS-FNB is an ideal specimen for use as a liquid biopsy for PC.

Diagnostic and therapeutic role of endoscopic ultrasound in liver diseases: A systematic review and meta-analysis.

BACKGROUND: In hepatology, the clinical use of endoscopic ultrasound (EUS) has experienced a notable increase in recent times. These applications range from the diagnosis to the treatment of various liver diseases. Therefore, this systematic review summarizes the evidence for the diagnostic and therapeutic roles of EUS in liver diseases. AIM: To examine and summarize the current available evidence of the possible roles of the EUS in making a suitable diagnosis in liver diseases as well as the therapeutic accuracy and efficacy. METHODS: PubMed, Medline, Cochrane Library, Web of Science, and Google Scholar databases were extensively searched until October 2023. The methodological quality of the eligible articles was assessed using the Newcastle-Ottawa scale or Cochrane Risk of Bias tool. In addition, statistical analyses were performed using the Comprehensive Meta-Analysis software. RESULTS: Overall, 45 articles on EUS were included (28 on diagnostic role and 17 on therapeutic role). Pooled analysis demonstrated that EUS diagnostic tests had an accuracy of 92.4% for focal liver lesions (FLL) and 96.6% for parenchymal liver diseases. EUS-guided liver biopsies with either fine needle aspiration or fine needle biopsy had low complication rates when sampling FLL and parenchymal liver diseases (3.1% and 8.7%, respectively). Analysis of data from four studies showed that EUS-guided liver abscess had high clinical (90.7%) and technical success (90.7%) without significant complications. Similarly, EUS-guided interventions for the treatment of gastric varices (GV) have high technical success (98%) and GV obliteration rate (84%) with few complications (15%) and rebleeding events (17%). CONCLUSION: EUS in liver diseases is a promising technique with the potential to be considered a first-line therapeutic and diagnostic option in selected cases.

A 49-Year-Old Man With Fever and Dyspnea After Endobronchial Ultrasound-Guided Transbronchial Fine Needle Aspiration Biopsy.

CASE PRESENTATION: A 49-year-old man, a farmer, had been experiencing coughing, phlegm, and difficulty breathing for 2 months. He underwent a CT scan at a local hospital that showed a mediastinal mass. Bronchoscopy showed no obstruction in the tracheal lumen, and an endobronchial ultrasound-guided transbronchial fine needle aspiration (EBUS-TBNA) biopsy was performed on the mediastinal mass. The cytologic smear of the mediastinal mass showed a few atypical epithelial cells; the possibility of a tumor could not be ruled out. The patient visited our thoracic surgery outpatient department; based on the advice of the thoracic surgeon, the patient underwent another endobronchial ultrasound-guided transbronchial fine needle aspiration biopsy of the mediastinal mass 4 days before this admission. The patient went home and waited for the results. Two days later, the patient experienced a fever and palpitations accompanied by chills, yellow phlegm, and orthopnea. The patient visited our ED, underwent tracheal intubation, and was admitted to our ICU. The patient had had occasional coughing and phlegm for the past 10 years, which were not taken seriously or investigated. The patient does not smoke or drink alcohol, and there is no history of cancer in the family.

[Role of General Anesthesia and Rapid On-site Evaluation 
in the Diagnosis of Lung Cancer with EBUS-TBNA].

BACKGROUND: Lung cancer is a common malignant tumor of respiratory system. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a valuable tool for the diagnosis and staging of lung cancer. EBUS-TBNA is predominantly performed under local anesthesia or conscious sedation. However, the diagnostic performance of EBUS-TBNA under general anesthesia and in conjunction with rapid on-site evaluation (ROSE) remains uncertain. This study aims to investigate the value of general anesthesia and ROSE in the diagnosis of lung cancer with EBUS-TBNA. METHODS: A retrospective analysis was conducted on 164 patients treated in the Department of Respiratory and Critical Care Medicine of The Affiliated Hospital of Southwest Medical University from January 2018 to December 2022. All patients were preoperatively suspected of lung cancer and underwent EBUS-TBNA. Based on whether they received general anesthesia and ROSE, the patients were divided into three groups: local anesthesia group (LA group)(n=54), general anesthesia group (GA group)(n=67) and general anesthesia with ROSE group (GA-ROSE group)(n=43). The puncture characteristics and diagnostic differences were analyzed among the groups. RESULTS: The number of lymph node puncture needles in the LA group was higher than in GA-ROSE group (P<0.01). The overall diagnostic rates of EBUS-TBNA for the three groups were 87.04%, 89.55% and 90.70%, respectively, with malignant tumor diagnostic rates of 88.24%, 88.89% and 94.74%. No statistically significant differences were observed among the three groups (P>0.05). There were no instances of severe complications or adverse anesthesia reactions in any of the groups. CONCLUSIONS: Compared to the combination of local anesthesia with intravenous analgesia and sedation, the implementation of EBUS-TBNA under general anesthesia, with or without ROSE, achieves equally accurate results, and general anesthesia combined with ROSE can reduce in the number of lymph node puncture needles.

Transbronchial lymph node forceps biopsy as a novel tool in diagnosis of mediastinal lymphadenopathy: a pilot study.

BACKGROUND: Differential diagnosis of mediastinal lymphadenopathy is an issue of debate. Lymph nodes may be enlarged due to a variety of inflammatory, infectious, or malignant reasons. Therefore, obtaining samples from the affected nodes is crucial for the diagnosis. Usually, these patients are subjected to TBNA (EBUS or conventional) or mediastinoscopy if TBNA is not conclusive. This study evaluated the safety and feasibility of this new technique of transbronchial forceps biopsy for the diagnosis of mediastinal lymphadenopathy. METHODS: The study included 18 patients with confirmed mediastinal lymphadenopathy who were admitted in Chest Department, Cairo University in the period from December 2019 to December 2020. All patients were subjected to flexible bronchoscopy with conventional transbronchial needle aspiration (C-TBNA) and transbronchial forceps biopsy (LN-TBFB) from the enlarged mediastinal lymph node in the same procedure. RESULTS: we found the technique of LN-TBFB safe with no serious complications. We were able to reach a diagnosis in 7/7 (100%) cases of sarcoidosis, 6/7 (85.7%) cases of malignant lymph nodes. We had three cases where the histopathology showed hyperactive follicular hyperplasia, and a single case of tuberculous lymphadenitis. C-TBNA was diagnostic in 71.4% of sarcoidosis cases, 42.9% of malignant cases, but failed to diagnose the one patient with tuberculous lymphadenitis. CONCLUSION: Lymph node transbronchial forceps biopsy (LN-TBFB) was found to be safe and effective in the diagnosis of mediastinal lymphadenopathy. We strongly advocate the use of this minimally invasive technique for diagnosing pathologically enlarged mediastinal lymph nodes, as a last step before mediastinoscopy.

High-Performance PMN-PT Single-Crystal-Based 1-3 Composite Transducer Integrated with a Biopsy Needle.

To address the need for high-resolution imaging in lung nodule detection and overcome the limitations of the shallow imaging depth associated with high-frequency ultrasound and the complex structure of lung tissue, we successfully integrated 50 MHz ultrasound transducers with 18-gauge biopsy needles. Featuring a miniaturized size of 0.6 × 0.5 × 0.5 mm3, the 50 MHz micromachined 1-3 composite transducer was tested to perform mechanical scanning of a nodule within a lung-tissue-mimicking phantom in vitro. The high-frequency transducer demonstrated the ability to achieve imaging with an axial resolution of 30 µm for measuring nodule edges. Moreover, the integrated biopsy needle prototype exhibited high accuracy (1.74% discrepancy) in estimating nodule area compared to actual dimensions in vitro. These results underscore the promising potential of biopsy-needle-integrated transducers in enhancing the accuracy of endoscopic ultrasound-guided fine needle aspiration biopsy (EUS-FNA) for clinical applications.

Accuracy of endobronchial ultrasound-guided transbronchial needle aspiration for staging of non-small cell lung cancer.

BACKGROUND: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is routinely performed to confirm a lung cancer diagnosis and/or to clinically stage disease. EBUS-TBNA findings may be used to determine whether patients can be offered potentially curative surgery. In this study, we evaluated the reporting in our service of EBUS-TBNA cytology for early-stage (operable) non-small cell lung cancer (NSCLC), focusing on diagnostic accuracy and analyzing cases with discordant cytologic and post-surgical histopathologic conclusions. METHODS: Cytology slides and cytopathology reports of 120 NSCLC patients who had undergone EBUS-TBNA and lobectomy in our hospital system between 2015 and 2021 were retrospectively reviewed. RESULTS: Of 290 lymph nodes (110 cases) able to be reviewed, interpretation of 48 lymph nodes was discordant with the original cytopathology report. This included 31 lymph nodes originally reported as adequate, which were found to be non-diagnostic on review. The diagnostic accuracy (benign/malignant) of lymph nodes that were sampled at EBUS-TBNA and excised at surgery was 89%. Specific examination of cases where EBUS-TBNA cytology did not reflect post-surgical findings illustrated important features and limitations of the procedure. These included potential misclassification of lymph node stations, the presence of multiple, variably involved nodes at lymph node stations, and the failure to detect small volume disease. CONCLUSIONS: Continuous evaluation of EBUS-TBNA performance identifies technical limitations and areas of improvement for cytopathology reporting. This is increasingly important in an era where lung cancer screening is expected to increase diagnosis of early-stage disease and with the advent of novel treatments, including non-surgical management options.

Insufficient endobronchial ultrasound-guided transbronchial needle aspiration specimens. When and why? The analysis of criteria and reasons behind the insufficient specimens.

BACKGROUND: The classification terminology systems for pulmonary cytology specimens have recently emerged. Inadequate samples, classified as "nondiagnostic," raise challenges in determining the threshold of cell numbers and the risk of malignancy (ROM). METHODS: The study retrospectively reviewed 248 endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) samples: 46 insufficient samples, 60 low cellularity samples, and 142 adequate samples. Characteristics as cellularity, number of benign and malignant cells, and background features were assessed. Receiver operating characteristic curve analysis was performed to establish cell sufficiency thresholds for the diagnosis. RESULTS: Out of the 248 samples analyzed, 108 were classified as benign, 94 as malignant, and 46 as insufficient. The study found that the cellularity thresholds for diagnosis in cell blocks and cytological samples were ≥50 cells and ≥100 cells, respectively. The thresholds for tumor cell counts were ≥1 - 10 cells for both types of cells, respectively. Considerably, some low cellularity samples were initially classified as insufficient despite meeting the diagnostic thresholds upon revision. The ROM varied across sample categories, with insufficient samples having a ROM of 10.9%, benign samples 15.7%, suspicious samples 92.0%, and malignant samples 100%. CONCLUSION: Insufficient EBUS-TBNA samples raise challenges in diagnosis and management. This study identified the root cause of insufficient samples, including factors related to humans, diagnostic methods, sampling, and laboratory processing. By understanding the root causes, diagnostic recommendations can be developed to improve the diagnostic process. The findings emphasize the importance of standardized classification and terminology systems for clear communication among healthcare professionals and institutions, ultimately improving patient care and enabling quality assurance measures.

Molecular analysis of endobronchial ultrasound needle aspirates in patients with non-small cell lung cancer: Results from the SCOPE database.

OBJECTIVE: Molecular subtyping of non-small cell lung cancer (NSCLC) is critical in the diagnostic evaluation of patients with advanced disease. This study aimed to examine whether samples from endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) of intrathoracic lymph nodes and/or lung lesions are adequate for molecular analysis across various institutions. METHODS: We retrospectively reviewed all cases of linear EBUS-TBNA with a final bronchoscopic diagnosis of NSCLC entered in the Stather Canadian Outcomes registry for chest ProcEdures database. The primary outcome was specimen inadequacy rate for each molecular target, as defined by the local laboratory or pathologist. RESULTS: A total of 866 EBUS-TBNA procedures for NSCLC were identified. Specimen inadequacy rates were 3.8% for EGFR, 2.5% for ALK-1 and 3.5% for PD-L1. Largest target size was not different between adequate and inadequate specimens, and rapid onsite evaluation did not increase specimen adequacy rates. One centre using next-generation sequencing for EGFR had lower adequacy rates than 2 others using matrix-assisted laser desorption/ionization time-of-flight mass spectrophotometry. CONCLUSION: EBUS-TBNA specimens have a very low-specimen inadequacy rate for molecular subtyping of non-small cell lung cancer.

Role of endoscopic ultrasound-guided fine needle aspiration biopsies in diagnosing pancreatic neoplasms in the paediatric population: experience from a tertiary center and review of the literature.

BACKGROUND: Endoscopic ultrasound-guided fine needle aspiration biopsy (EUS FNAB) is a well established diagnostic method in adult patients, but is rarely used in the paediatric population. The Clinical Department of Gastroenterology at the University Clinical Centre Ljubljana and the Department of Cytopathology at the Institute of Pathology, Faculty of Medicine, University of Ljubljana, Slovenia, have been closely collaborating on EUS FNAB since the introduction in 2010. The aim of the study was to review the cases of EUS FNAB of pancreatic neoplasms in children. PATIENTS AND METHODS: In the digital archive of the Institute of Pathology (IP), Faculty of Medicine (FM), University of Ljubljana (UL), we found 6 cases of EUS FNAB in children, 3 had EUS FNAB of the pancreas, 2 of whom had a cytopathologic diagnosis of a tumour. In the first case, the lesion was ultrasonographically solid, and the cell sample contained branching papillary structures surrounded by aggregates of small cells with nuclear grooves. In the second case, the lesion was ultrasonographically cystic, and predominantly necrosis was seen, with only single preserved cells. Positive nuclear reaction for ß-catenin was found in both cases by immunohistochemical staining. RESULTS: In both cases, the cytopathological diagnosis of solid pseudopapillary neoplasm of the pancreas was made, the cases represent the totality of paediatric cases of pancreatic neoplasms from the Children's Hospital Ljubljana since 2010. There were no adverse events during and after EUS FNAB. A histopathological examination of the tumour resection specimens confirmed the cytopathological diagnosis. CONCLUSIONS: Our experience indicates that EUS FNAB is a safe and effective method for diagnosing pancreatic neoplasms in the pediatric population, as supported by the findings in the literature.

Droplet digital polymerase chain reaction detection of KRAS mutations in pancreatic FNA samples: Technical and practical aspects for routine clinical implementation.

BACKGROUND: Pancreatic adenocarcinoma (PDAC) is associated with a 5-year survival rate of less than 6%, and current treatments have limited efficacy. The diagnosis of PDAC is mainly based on a cytologic analysis of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) samples. However, the collected specimens may prove noncontributory in a significant number of cases, delaying patient management and treatment. The combination of EUS-FNA sample examination and KRAS mutation detection can improve the sensitivity for diagnosis. In this context, the material used for molecular analysis may condition performance. METHODS: The authors prospectively compared the performance of cytologic analysis combined with a KRAS droplet digital polymerase chain reaction (ddPCR) assay for PDAC diagnosis using either conventional formalin-fixed, paraffin-embedded cytologic samples or needle-rinsing fluids. RESULTS: Molecular testing of formalin-fixed, paraffin-embedded cytologic samples was easier to set up, but the authors observed that the treatment of preanalytic samples, in particular the fixation process, drastically reduced ddPCR sensitivity, increasing the risk of false-negative results. Conversely, the analysis of dedicated, fresh needle-rinsing fluid samples appeared to be ideal for ddPCR analysis; it had greater sensitivity and was easily to implement in clinical use. In particular, fluid collection by the endoscopist, transportation to the laboratory, and subsequent freezing did not affect DNA quantity or quality. Moreover, the addition of KRAS mutation detection to cytologic examination improved diagnosis performance, regardless of the source of the sample. CONCLUSIONS: Considering all of these aspects, the authors propose the use of an integrated flowchart for the KRAS molecular testing of EUS-FNA samples in clinical routine.

An Unusual Etiology of Fluorodeoxyglucose Avid Intrathoracic Lymph Nodes.

A middle-aged man in his 50s, active smoker, presented to the pulmonary office for lung cancer evaluation. On a low-dose computed tomography for lung cancer screening, he was found to have an 8 mm endobronchial lesion in the right main stem bronchus. A PET-CT revealed no endobronchial lesion, but incidentally, fluorodeoxyglucose (FDG) avidity was present in the right hilar (SUV 13.2) and paratracheal lymph nodes (LNs). He underwent bronchoscopy and EBUS-TBNA of station 7 and 10 R LNs. The fine needle aspiration (FNA) revealed necrotizing epithelioid granuloma. The acid-fast bacilli (AFB) and Grocott methenamine silver (GMS) stains were negative. He had suffered from pneumonic tularemia 13 months ago and immunohistochemical staining for Francisella tularensis on FNA samples at Center for Disease Control and Prevention was negative. The intense positron emission tomography (PET) avidity was attributed to prior tularemic intrathoracic lymphadenitis without active tularemia, a rare occurrence. To the best of our knowledge, PET-positive intrathoracic lymph node beyond one year without evidence of active tularemia has not been previously reported.