Endoscopic Ultrasound-guided Fine-needle Aspiration Research Articles

Safety of endoscopic ultrasound-guided fine-needle aspiration for pancreatic solid mass in the elderly: A single-center retrospective study.

There are few reports on the safety of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in the elderly. In this study, we investigated the safety of EUS-FNA for pancreatic solid masses in patients aged ≥80 years. This is a single-center retrospective study. A total of 600 patients with pancreatic solid masses who underwent EUS-FNA under midazolam-based sedation at our institution between September 2016 and December 2022 were enrolled in this study. Eligible patients were divided into two groups: an elderly group aged ≥80 (n = 84), as well as a nonelderly group aged ≤79 (n = 516). These two groups were compared. The elderly group required significantly fewer midazolam doses for sedation (P < 0.001). Adverse events occurred in eight patients (1.3%), including one (1.2%) and seven (1.4%) in the elderly and nonelderly groups, respectively (P = 0.90). There were no cases of early adverse events in the elderly group and six cases (1.2%) in the nonelderly group (P = 0.32). There was one case of late adverse events in both the elderly and nonelderly groups (P = 0.14), and both were needle tract seeding. There was no significant difference between the two groups in the proportion of cases in which percutaneous oxygen saturation decreased to ≤90% during the EUS-FNA. Our analysis suggests that EUS-FNA for pancreatic solid masses can be safely performed in patients aged >80 years without increasing the adverse event rate compared to nonelderly patients aged <80 years. Geriatr Gerontol Int 2023; 23: 836-841.

The role of needle-based confocal laser endomicroscopy in the diagnosis of pancreatic neuroendocrine tumors.

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is a highly accurate method for diagnosing pancreatic neuroendocrine tumors (PNETs); however, some PNETs are difficult to diagnose. Recently, the efficacy of needle-based confocal laser endomicroscopy (nCLE) in diagnosing solid pancreatic masses has been reported. However, the efficacy of nCLE in the diagnosis of PNETs remains unknown and only a small number of cases have been reported. Hence, this study aimed to evaluate the efficacy of nCLE in the diagnosis of PNETs. This single-center retrospective study evaluated 30 consecutive patients with suspected PNETs on contrast-enhanced computed tomography, who consented to nCLE combined with EUS-FNA and were diagnosed using EUS-FNA or surgical resection. The diagnostic criteria for PNETs using nCLE were based on the nesting and trabecular and glandular arrangement of tumor cell clusters surrounded by capillary vessels and fibrosis, as reported in previous studies. The diagnosis using nCLE was classified into three categories: misdiagnosis in three cases (10%), non-diagnostic in six cases (20%), and diagnostic in 21 cases (70%). nCLE was able to diagnose PNET in one of the two cases with inconclusive EUS-FNA. Although further development of the resolution and optimization of the diagnostic criteria are required, nCLE may constitute a useful diagnostic option in cases of inconclusive EUS-FNA for PNETs.

The yield of cytology and histology obtained by endoscopic ultrasound-guided fine needle aspiration and biopsy needles in the diagnosis of pancreatic adenocarcinoma.

Endoscopic ultrasound-guided fine needle aspiration and biopsy (EUS-FNA, -FNB) are the mainstay for tissue diagnosis of pancreatic lesions. Traditionally, FNA was performed for obtaining cytology and also histology if available from the puncture. Since their advent, however, FNB needles have been intended mainly to obtain core biopsies for histological specimens. We aimed to assess the yield of cytology obtained via both FNA and FNB needles. A retrospective study was performed including all patients who were diagnosed with pancreatic adenocarcinoma obtained via EUS-FNA/FNB needles. Overall, 227 patients were included. Of them, 85 patients underwent FNB, versus 142 patients who had FNA. The average age in the FNB group was 70.46 ± 11.29 years, versus 71.44 ± 11.80 in the FNA group, P = 0.57. Notably, cytological analysis diagnosed malignancy equally in both groups (69.4% in the FNB group, vs. 65.5% in the FNA group). The compatibility rate of cytology with histology was 76.5% in the FNB group, versus 76.1% in the FNA group (P = 0.69). The agreement level between cytology obtained by FNA and FNB, versus histology obtained by both needles, was moderate (kappa = 0.48, 95% CI 0.39-0.57). Similarly, the agreement level between cytology and histology in the FNB group was moderate as well (kappa = 0.5, 95% CI 0.36-0.64). Cytological assessment yielded an equal performance as compared to histological assessment with both needles. We recommend obtaining cytology specimens in pancreatic solid lesion puncture by FNB needle.

Current status and issues in genomic analysis using EUS-FNA/FNB specimens in hepatobiliary-pancreatic cancers.

Comprehensive genomic profiling based on next-generation sequencing has recently been used to provide precision medicine for various advanced cancers. Endoscopic ultrasound (EUS)-guided fine-needle aspiration (EUS-FNA) and EUS-guided fine-needle biopsy (EUS-FNB) play essential roles in the diagnosis of abdominal masses, mainly pancreatic cancers. In recent years, CGP analysis using EUS-FNA/FNB specimens for hepatobiliary-pancreatic cancers has increased; however, the success rate of CGP analysis is not clinically satisfactory, and many issues need to be resolved to improve the success rate of CGP analysis. In this article, we review the transition from EUS-FNA to FNB, compare each test, and discuss the current status and issues in genomic analysis of hepatobiliary-pancreatic cancers using EUS-FNA/FNB specimens.

EUS-guided fine needle aspiration-based clues to mistaken or uncertain identity: serous pancreatic cysts

Background/ObjectivesPancreatic serous cystic neoplasms (SCN) present a diagnostic challenge given their increasing frequency of detection and benign nature yet relatively high rate of misdiagnosis. Here, imaging and analyses associated with EUS-guided fine-needle aspiration (EUS-FNA) are evaluated for their ability to provide a correct preoperative diagnosis of SCN. MethodsA surgical cohort with confirmed pathological diagnosis of SCN (n = 62) and a surveillance cohort with likely SCN (n = 31) were assessed for imaging (CT/MRI/EUS) and EUS-FNA-based analyses (cytology/DNA analysis for Von Hippel-Lindau [VHL] gene alterations/biomarkers). ResultsIn the surgical cohort, CT/MRI and EUS respectively predicted SCN in 4 of 58(7%) and 19 of 62(31%). Cyst fluid cytology and VHL alterations predicted SCN in 1 of 51(2%) and 5 of 21(24%), respectively. High specificity cyst fluid biomarkers (vascular endothelial growth factor [VEGF]/glucose/carcinoembryonic antigen [CEA]/amylase) correctly identified SCN in 25 of 27(93%). In the surveillance cohort, cyst fluid biomarkers predicted SCN in 12 of 12(100%) while VHL alterations identified SCN 3 of 10(30%). ConclusionHigh specificity cyst fluid biomarkers provided the most sensitive means of diagnosing SCN preoperatively. To obtain a preoperative diagnosis of SCN at the highest level of certainty, a multidisciplinary approach should be taken to inform appropriate SCN management.

Comparison of 19-gauge conventional and Franseen needles for the diagnosis of lymphadenopathy and classification of malignant lymphoma using endoscopic ultrasound fine-needle aspiration.

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) using a 19-gauge needle is an efficient sampling method for the diagnosis of lymphadenopathy. This study compared 19-gauge conventional and Franseen needles for the diagnosis of lymphadenopathy and classification of malignant lymphoma (ML). Patient characteristics, number of needle passes, puncture route, sensitivity, specificity, and accuracy of cytology/histology for lymphadenopathy were analyzed in patients diagnosed with lymphadenopathy by EUS-FNA using conventional or Franseen needles. Between 2012 and 2022, 146 patients met the inclusion criteria (conventional [n=70] and Franseen [n=76]). The median number of needle passes was significantly lower in the conventional group than in the Franseen group (3 [1-6] vs. 4 [1-6], p=0.023). There were no significant differences in cytological/histological diagnoses between the two groups. For ML, the immunohistochemical evaluation rate, sensitivity of flow cytometry, and cytogenetic assessment were not significantly different in either group. Bleeding as adverse events (AEs) were observed in three patients in the Franseen group. Both the 19-gauge conventional and Franseen needles showed high accuracy in lymphadenopathy and ML classification. Considering sufficient tissue collection and the avoidance of AEs, the use of 19-gauge conventional needles seems to be a good option for the diagnosis of lymphadenopathy.

Endoscopic Ultrasonography-Guided Fine-Needle Aspiration for Duodenal Subepithelial Lesions Showing a Hypoechoic Mass on Endoscopic Ultrasound Imaging.

For duodenal subepithelial lesions showing a hypoechoic mass on endoscopic ultrasound imaging, the utility of endoscopic ultrasound-guided fine-needle aspiration and the frequency of histological types have not been the focus of previous literature. This study aimed to clarify this. This prospective observational study enrolled 22 consecutive patients who underwent endoscopic ultrasoundguided fine-needle aspiration for duodenal subepithelial lesions with hypoechoic mass on endoscopic ultrasound. Immunohistochemical analysis was performed for all endoscopic ultrasound-guided fine-needle aspiration and surgically resected specimens. The main outcome measures were the technical results of endoscopic ultrasound-guided fine-needle aspiration and the frequency of histological types of duodenal subepithelial lesions with hypoechoic mass. Thirteen fine-needle aspiration specimens were obtained from the duodenal bulb and eight from the descending duodenal region. The puncture was not performed because of intervening vessels in one patient. The diagnostic rate was 81% (95% confidence interval: 58.1-94.6, 17/21 patients). In 12 patients receiving surgical resection (excluding one cancellation of endoscopic ultrasoundguided fine-needle aspiration), the diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration was 75% (95% confidence interval: 42.8-94.5, 9/12 patients). No complications were observed. The histopathological diagnoses included 11 cases of gastrointestinal stromal tumor (50%), 2 cases of leiomyoma (9%), 2 cases of metastatic cancer (9%), 2 cases of benign inconclusive, and 1 case each of carcinoid, malignant lymphoma, leiomyosarcoma, gauzeoma, and aberrant pancreas (4.5% each). The frequency of malignant tumors in the duodenal subepithelial lesions with hypoechoic mass group was 73% (16/22 patients). Endoscopic ultrasound-guided fine-needle aspiration for duodenal subepithelial lesions with hypoechoic mass was safe and accurate. As duodenal subepithelial lesion with hypoechoic mass has a reasonably high possibility of containing malignant tumors, it is desirable to perform endoscopic ultrasound-guided fine-needle aspiration.

Risk Factors and Interpretation of Inconclusive Endoscopic Ultrasound-Guided Fine Needle Aspiration Cytology in the Diagnosis of Solid Pancreatic Lesions.

The inconclusive cytological findings of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) remain a major clinical challenge and often lead to treatment delays. Patients who had undergone EUS-FNA sampling for solid pancreas lesions between 2014 and 2021 were retrospectively enrolled. The "atypical" and "non-diagnostic" categories of the Papanicolaou Society of Cytopathology System were considered inconclusive and the "negative for malignancy" category of malignancy was suspected clinically. We determined the frequency and predictors of inconclusive cytological finding. A total of 473 first EUS-FNA samples were included, of which 108 cases (22.83%) were inconclusive. Significant increases in the odds of inconclusive cytological findings were observed for lesions with a benign final diagnosis (OR 11.20; 95% CI 6.56-19.54, p < 0.001) as well as with the use of 25 G FNA needles (OR 2.12; 95% CI 1.09-4.01, p = 0.023) compared to 22 G needles. Furthermore, the use of a single EUS-FNA technique compared to the combined use of slow-pull and standard suction techniques (OR 1.70; 95% CI 1.06-2.70, p = 0.027) and less than three punctures per procedure led to an elevation in the risk of inconclusive cytology (OR 2.49; 95% CI 1.49-4.14, p < 0.001). Risk reduction in inconclusive cytology findings was observed in lesions between 2-4 cm (OR 0.40; 95% CI 0.23-0.68, p = 0.001) and >4 cm (OR 0.16; 95% CI 0.08-0.31, p < 0.001) compared to lesions ≤2 cm. The more than two punctures per EUS-FNA sampling with larger-diameter needle (19 G or 22 G) using the slow-pull and standard suction techniques in combination may decrease the probability of inconclusive cytological findings.

Diagnostic role of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in abdominal lymphadenopathy of unknown etiology.

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is an established method for the evaluation of abdominal organ lesions. However, there are few studies on EUS-FNA for abdominal lymph node (LN) lesions. The purpose of this study was to evaluate the diagnostic role of EUS-FNA in isolated abdominal lymphadenopathy (LAP). A retrospective analysis was performed on patients with isolated abdominal LAP who underwent a EUS-FNA examination. The diagnosis was made based on cytology, histology, and immunohistochemical (IHC) studies. The area under curve (AUC) value, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. A total of 99 patients were included in this study. The final diagnoses were metastatic tumor (n = 32), lymphoma (n = 32), tuberculosis (n = 17), sarcoidosis (n = 5), castleman's disease (n = 1), and reactive LAP (n = 12). The AUC value, sensitivity, specificity, PPV, NPV, and accuracy of EUS-FNA in the diagnosis of malignant LAP were 0.9531, 90.6, 100, 100, 85.4, and 93.9%, respectively. For the diagnosis of lymphoma, the accuracy of EUS-FNA combined with IHC staining was 94.9%. Retroperitoneal LN enlargement is more commonly associated with lymphoma, while hepatic hilar LN enlargement predominantly suggests benign conditions or metastatic tumors. Malignant lymph nodes are more likely to be regular border, circular/quasi-circular, and fusion. Lymphomas are more likely to present with fusion and heterogeneous echogenicity than metastatic tumors. EUS-FNA is a safe and effective method to diagnose isolated abdominal LAP.

Comparison of Fine-Needle Biopsy (FNB) versus Fine-Needle Aspiration (FNA) Combined with Flow Cytometry in the Diagnosis of Deep-Seated Lymphoma.

Evidence comparing ultrasound endoscopy-guided fine-needle biopsy (EUS-FNB) with EUS-guided fine-needle aspiration (EUS-FNA) in deep-seated lymphoma tissue sampling is insufficient. This study aims to evaluate the diagnostic efficacy of immunohistochemistry (IHC) or flow cytometry (FCM) on specimens obtained from EUS-FNB and EUS-FNA in the diagnosis and staging of deep-seated lymphomas. This real-world, dual-center study prospectively evaluated all eligible specimens from patients who underwent EUS-FNB/FNA over an 8-year period. 53 patients were enrolled, with 23 patients in the EUS-FNB group and 30 patients in the EUS-FNA group. FNB yielded specimens with longer core tissues (0.80 mm [0.55, 1.00] vs. 0.45 mm [0.30, 0.50], p = 0.009) and higher scores of specimen adequacy [4 (3.75, 4.00) vs. 3 (1.00, 4.00), p = 0.025]. Overall analysis revealed that the diagnostic accuracy of IHC based on specimens acquired from EUS-FNB was significantly higher than that of EUS-FNA (91.30% vs. 60.00%, p = 0.013). After controlling confounding factors including lesion size and endoscopists, EUS-FNB with IHC maintained a higher-level diagnostic accuracy compared to EUS-FNA (OR = 1.292 [1.037-1.609], p = 0.023). When FCM was additionally used to analyze the specimen acquired from EUS-FNA, the diagnostic yield was significantly improved (ROC AUC: 0.733 vs. 0.550, p = 0.015), and the AUC of FNB alone or combined with FCM was 0.739 and 0.761. Conclusions: FNB needles generate higher histopathological diagnostic accuracy and specimen quality than FNA for the deep-seated lymphoma. Though the application of FCM significantly improves the diagnostic efficacy of EUS-FNA, FNB was still the preferred diagnostic modality with a shorter procedure time, comparable diagnostic accuracy, and better cost-effectiveness.

Role of EBUS-TBNA/EUS-FNA and mass spectrometry for diagnosis and typing of lymph node amyloidosis: 10-year experience in two tertiary care academic centers.

The objectives of this study were to investigate the utility of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA)/endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for the diagnosis of amyloidosis coupled with the feasibility of mass spectrometry (MS) for amyloid subtyping. All patients who had amyloid diagnosed by EBUS-TBNA/EUS-FNA at two tertiary care centers from 2011 to 2020 were retrieved along with the MS subtype, clinical findings, and outcomes. Eight patients were included: seven underwent EBUS-TBNA of mediastinal lymph nodes, and one underwent EUS-FNA of a periportal lymph node. Ages ranged from 37 to 79years (median, 69 years), with equal numbers of men and women. Presenting clinical history included one case each of follicular lymphoma, lymphoplasmacytic lymphoma, rheumatoid arthritis, possible sarcoid, cirrhosis, and chronic renal insufficiency, and one case each of suspected pulmonary and cardiac amyloidosis. All cases showed waxy, amorphous material on direct smears (n=5) or ThinPrep slides (n=3), which were confirmed as amyloid on Congo Red staining. Immunohistochemistry showed dominant lambda staining in two of three cases. MS was performed in all cases and identified five of the light-chain (AL) type, one of the heavy-chain/AL type, and two suggestive of AL amyloidosis. Bone marrow biopsy performed in seven patients demonstrated that three had monoclonal plasma cells and one had lymphoplasmacytic lymphoma. Two of four patients with systemic amyloidosis received chemotherapy and remained alive, whereas three with localized disease remained stable under observation. EBUS-TBNA/EUS-FNA is effective for amyloidosis diagnosis and provides adequate material for ancillary tests, including MS, which can identify the precursor amyloidogenic protein, leading to appropriate patient management.

Comparison of Standard Fine Needle Aspiration versus Fine Needle Biopsy for Endoscopic Ultrasound Guided Sampling of Solid Lesions

Abstract Background Endoscopic ultrasound (EUS) -guided tissue acquisition is the standard of care for the diagnosis of solid pancreatic lesions. Traditionally, sampling is performed through fine-needle aspiration and the diagnosis is made through cytology. The challenge in solid pancreatic lesions is that they are often fibrotic, with significant necrosis limiting the cellularity of samples obtained via fine-needle aspiration. Aim of the Work The aim of the current study was to compare fine needle aspiration versus fineneedle biopsy for the diagnostic yield of malignancy. - The secondary objectives are to compare fine needle aspiration versus fine-needle biopsy for: 1) The overall diagnostic yield from solid lesions. 2) The diagnostic yield from pancreatic and nonpancreatic solid lesions. 3) The crossover diagnostic yield. 4) The sample quality obtained by either the slow-pull or suction approaches, respectively. Patients and Methods This is a cross-sectional study, included 92 patients (52 male and 40 female), age ranges from (18-80 y); with indeterminate pancreatic lesions and gastric lesions selected randomly from April 2021 till March 2022 from the outpatient clinics of Theodor Bilharz Research Institute. Results The most common lesion founded in fine needle aspiration group by CT or MRI was Pancreatic soft tissue mass in 86.9% and in the fine needle Biopsy group was also Pancreatic soft tissue mass in 80.4% with a statistically difference in between. The most common lesion founded in FNA group by EUS was Pancreatic soft tissue mass in 73.9% and in the FNB group was also Pancreatic soft tissue mass in 89.1% with a statistically difference in between. The cytologic examination shows 60.8% of FNA group and 69.5% of FNB group are malignant lesions. the majority of the lesions were Pancreatic adenocarcinoma in the FNA group was 47.8% and in FNB group was 56.5%. The sensitivity was 97.8% versus 92.5%, specificity 96.4% versus 92.8%, PPV 95% versus 90%, NPV 100% versus 96%, and accuracy 97.2% versus 92.7% for FNA and FNB, respectively Conclusion EUS-FNA is superior to EUS-FNB in sampling pancreatic masses. EUS-guided FNA and FNB are safe, appropriate procedures that have comparable diagnostic accuracy for solid lesions within the gastrointestinal tract. The 22-G FNB needles are easy handling in anatomically challenging locations and required fewer needle passes to reach diagnosis.

The World Health Organization classification of pancreaticobiliary cytopathology stratifies risk of malignancy and outcome for endoscopic ultrasound-guided fine-needle aspiration of the pancreas.

The World Health Organization (WHO) has recently published a classification for reporting pancreaticobiliary cytopathology with differences compared to the Papanicolaou Society of Cytopathology (PSC) classification. Retrospective data were collected from pancreatic endoscopic ultrasound-guided fine-needle aspirations from 2014 to 2017 at a pancreatic cancer center. Absolute risk of malignancy (AROM), relative risk (to benign), performance characteristics, and overall survival were calculated for the entire cohort with comparison of cysts and solid lesions. In total, 2562 cases were included: 16% cyst (n=411) and 84% solid (n=2151). The histologic confirmation rate was 43% (n=1101) and the median follow-up (for benign) was 56months. For WHO I-VII, overall AROM (%) was 23, 22, 62, 13, 65, 97, and 100; cyst AROM was 7, 0, 19, 13, 38, 78, and 100; and solid AROM was 50, 29, 70, 15, 100, 99, and 100. For PSC I-VI, overall AROM (%) was 23, 29, 64, 0 (IVa), 60 (IVb), 97, and 100; cyst AROM was 7, 0, 19, 0, 21, 78, and 100; and solid AROM was 50, 35, 73, 0, 92, 99, and 100. The difference in relative risk for a cyst (vs. solid) overall was 0.38 for WHO and 0.26 for PSC. WHO and PSC categories showed stratification for the probability of overall survival. Cystic versus solid lesion type can dramatically affect AROM, particularly for nondiagnostic (I), benign (II), atypical (III), and WHO V categories. WHO IV conveys a similarly low AROM for cystic and solid types. Both classifications stratify the probability of overall survival, including the newly introduced categories WHO IV and WHO V.

A review of contrast-enhanced harmonic endoscopic ultrasonography for pancreatic solid tumors.

Endoscopic ultrasonography (EUS) is superior to other imaging modalities in the detection of pancreatic masses, although differentiating the types of pancreatic masses detected on EUS remains challenging. However, the value of contrast-enhanced harmonic EUS (CH-EUS) using ultrasound contrast agents for this differentiation has been reported. CH-EUS plays a pivotal role in analysis of small lesions that can only be detected with EUS. Recently, CH-EUS was used for staging and/or determining the resectability of pancreatic cancer in several clinical trials. In addition, it is used to estimate the response of pancreatic cancer to chemotherapy and to determine the prognosis in cases of pancreatic cancer and pancreatic neuroendocrine neoplasms. It is also postulated that CH-EUS improves the diagnostic performance of endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) through complementary diagnoses using CH-EUS and EUS-FNAB, or CH-EUS-guided EUS-FNAB. Thus, CH-EUS has been employed for various qualitative diagnoses, including differentiation of pancreatic masses. Second-generation contrast agents such as Sonazoid are used clinically for ultrasound diagnostic imaging of liver and breast disease. The positioning of CH-EUS with Sonazoid as a test for the diagnosis of solid pancreatic tumors is an issue for further studies.

Endoscopic ultrasound-guided fine needle aspiration for a pericardial lesion.

Endoscopic ultrasound-guided fine needle aspiration for a pericardial lesion.

A resected case of malignant peripheral nerve sheath tumor arising in the cervical esophagus

We report herein a case of malignant peripheral nerve sheath tumor (MPNST), an extremely rare, esophageal malignancy. A 67-year-old, female patient presented with a nodular lesion in the cervical esophagus which was detected on follow-up computed tomography (CT) after surgery for bilateral breast cancer and gastric cancer. Upper gastrointestinal endoscopy revealed a hemispheric, submucosal lesion in the cervicothoracic esophagus. Endoscopic ultrasound-guided fine needle aspiration cytology revealed spindle-shaped cells with nuclear atypia and positive staining for the S100 protein, a neurogenic marker. Based on clear CT findings of lesion growth over two years, MPNST was diagnosed, and treatment for sarcoma was begun. After one course of preoperative chemotherapy, open resection of the esophagus was performed, revealing a solid, white tumor with a maximum diameter of 1.8 cm. The tumor was histopathologically found to be located within the intrinsic muscularis propria. Based on this finding, low-grade MPNST with a schwannoma-like component at its margins was diagnosed. Approximately 50% of MPNST cases occur against a background of neurofibromatosis type 1 (NF1) while about 40% occur sporadically, and 10% occur after irradiation. The patient’s history of radiotherapy for left breast cancer may have contributed to the development of the MPNST.

Mimickers of neuroendocrine tumors on endoscopic ultrasound-guided fine-needle aspirate material: Need for caution.

Cytologic diagnosis of neuroendocrine tumors can be straightforward on cytologic preparations, given the classical neuroendocrine morphology and expression of neuroendocrine markers confirmed by immunohistochemistry. However, overreliance on neuroendocrine markers can lead to misdiagnosis even if individual cell features suggest a neuroendocrine tumor. We present three unusual cases, two of which were initially diagnosed as neuroendocrine tumors and the third one carried preliminary diagnosis of neuroendocrine tumor on endoscopic ultrasound-guided fine-needle aspirates. These cases subsequently turned out to be cholangioblastic cholangiocarcinoma, metastatic melanoma, and gastric glomus tumor, respectively. We suggest approaches that could have pointed us towards the correct diagnosis at the outset and discuss potential pitfalls.

APPLICATION OF ENDOSCOPIC ULTRASOUND GUIDED FNAC(EUS-FNAC) IN DIAGNOSING PANCREATIC MASS LESIONS

Introduction: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNAC) has become an important modality for identification of pancreatic masses. It is a minimally invasive procedure that provides excellent cell yield even in deep seated lesions. The preoperative diagnosis of pancreatic mass by EUS-FNAC can help the surgeons in early detection and confirmation of neoplasm as pancreatic mass lesions are highly concerning for pancreatic carcinoma. This study was aimed at application of EUS-FNAC in diagnosing pancreatic mass lesions. Methods: A study was conducted for 20 cases who underwent EUS guided FNAC for pancreatic mass lesions. EUS-FNAC was performed by using a curvilinear array echo endoscope. The technique was carried out by a skilled endoscopist, and the glass slides were used to make smears from fluid that was aspirated containing corpuscular fractions. The slides were air dried before being examined cytopathologically. Results: Out of 20 cases,10 were of pancreatic Ductal adenocarcinoma, 3 of Neuroendocrine tumor of pancreas, 2 of Acinar cell carcinoma, 1 of Solid pseudopapillary tumor, 2 of Serous cystadenoma and 2 of Mucinous cystadenoma. This was confirmed later, on further Immunocytochemical stains. Conclusions:Out of 20 cases, 16 were malignant and 4 were benign. EUS-FNAC can help in early diagnosis and can improve the patient outcome. It is safe, cost-effective and reliable. It not only gives precise cytological diagnosis, but it also allows for the exact site of tiny lesions.

Endoscopic ultrasound-guided fine-needle aspiration for gastrointestinal subepithelial lesions.

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the first-choice procedure for obtaining pathological tissue samples from gastrointestinal (GI) subepithelial lesions (SELs). However, its diagnostic accuracy is lower than that for pancreatic masses owing to puncture difficulty and the need for immunostaining for definitive diagnosis. The advent of fine-needle biopsy needles, which have become well known in recent years, improves the diagnostic accuracy of EUS-FNA for GI SELs. The forward-viewing echoendoscope and rapid on-site evaluation (ROSE) have also helped to improve diagnostic accuracy. Furthermore, in facilities where ROSE is not available, endosonographers perform a macroscopic on-site evaluation. With these procedural innovations, EUS-FNA is now performed aggressively even for SELs smaller than 20mm. The incidence of procedure-related adverse events such as bleeding and infection is low, and thus, EUS-FNA can be safely performed to diagnose SELs.

Discordant microsatellite instability findings in two samples from a patient with biliary cancer that responded to pembrolizumab.

Microsatellite instability (MSI) is a key marker to predict response to immune checkpoint inhibitors; however, only 1-2% of biliary cancers have this genomic feature. In a patient with hilar biliary cancer, MSI was examined in two cancer specimens (forceps biopsy from the biliary stricture and endoscopic ultrasound-guided fine-needle aspiration biopsy [EUS-FNAB] from the adjacent lymph node). We observed discordant results, as high frequency of MSI was found only in the forceps biopsy. Although the FNAB sample was 10 times larger than that of the forceps biopsy, the tumor concentration was much lower, which is a possible reason for the discordance. Besides, immunohistochemistry of four mismatch-repair (MMR) proteins showed proficient MMR expressions. The tumor became refractory to gemcitabine, cisplatin, and S-1 but responded well to pembrolizumab. Caution is needed for sample selection and for interpretation of the test's results, to avoid missing rare chance for effective molecular target agents.