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OBJECTIVE: Assessing unclear biliary strictures is challenging. We analyzed the diagnostic performance of radiology, EUS, and ERCP. METHODS: All patients referred for EUS and ERCP to assess an unclear biliary stricture were prospectively included. The data from radiology, EUS, ERCP, and tissue sampling were recorded. The diagnostic modalities were analyzed separately and in combination, with a focus on PSC. RESULTS: Between 2013 and 2020, 78 patients were included; 31% had PSC. A cholangioscopy was not performed in this study. The final diagnosis indicated that the biliary stricture was benign in 62% of the patients and malignant in 38%. The differences among the modalities were numerical, not significant. The modalities showed an accuracy between 78 and 83% in all the patients and between 75 and 83% in the patients with PSC. The combination of radiology and EUS showed the highest sensitivity of 94% in all the patients and a sensitivity of 100% in PSC. Tissue sampling showed the highest specificity of 93% in all patients and 89% in PSC. In 22 cases with combined EUS, ERCP, and tissue sampling, the accuracy, sensitivity, and specificity were 82%, 70%, and 92%, respectively. Minor differences were observed between the intention-to-diagnose analysis and the per-protocol analysis. Adverse events were recorded in 4% of cases. CONCLUSION: The combination of EUS and ERCP with tissue sampling seems to be useful and safe for excluding malignancy in unclear biliary strictures. In cases with a reduced suspicion of malignancy, radiology with an EUS may be sufficient.
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Colangiopancreatografia Retrógrada Endoscópica , Colestasis , Endosonografía , Sensibilidad y Especificidad , Humanos , Masculino , Endosonografía/métodos , Femenino , Persona de Mediana Edad , Anciano , Constricción Patológica/diagnóstico por imagen , Estudios Prospectivos , Colestasis/diagnóstico por imagen , Colestasis/etiología , Adulto , Colangitis Esclerosante/diagnóstico por imagen , Colangitis Esclerosante/complicacionesRESUMEN
Background: Endoscopic ultrasound (EUS)-guided transmural drainage using double pigtail plastic stents (DPPS) has been routine for the treatment of peripancreatic fluid collections (PFC). Lumen-apposing metal stents (LAMS) have since their introduction been the preferred choice; however, their superiority has not been proven. The aim of this study was to compare the efficacy and safety of DPPS and LAMS. Methods: This was a single-center, prospective study that included consecutive patients undergoing EUS-guided drainage between January 2010 and December 2020. The primary endpoints were technical success, clinical success and adverse event rate, while the secondary endpoints included symptomatic relief, length of hospital stay, and need for adjunct drainage. A subgroup analysis of walled-off necrosis (WON) was performed. Results: A total of 89 patients (median age 56 years) underwent EUS-guided transmural drainage (DPPS: n=53; LAMS: n=36) because of a pseudocyst (n=37) or a WON (n=52). Both DPPS and LAMS had a 100% technical success rate and a comparable adverse event rate (4% vs. 6%, P=0.24). An equivalent efficacy was recorded for the drainage of PFC comparing DPPS and LAMS, and no significant statistical difference was recorded in clinical success (DPPS 60% vs. LAMS 61%, P=0.94) or the need for reintervention (DPPS 11% vs. LAMS 13%, P=0.72). Conclusions: In this large, prospective study of EUS-guided drainage of peripancreatic fluid collections, LAMS and DPPS showed equivalent safety, technical success, clinical success and hospital stay. Both techniques were associated with a comparable need for complementary necrosectomy.
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OBJECTIVE: Colorectal cancer (CRC) has a significant role in cancer-related mortality. Colonoscopy, combined with adenoma removal, has proven effective in reducing CRC incidence. However, suboptimal colonoscopy quality often leads to missed polyps. The impact of artificial intelligence (AI) on adenoma and polyp detection rate (ADR, PDR) is yet to be established. DESIGN: We conducted a randomised controlled trial at Sahlgrenska University Hospital in Sweden. Patients underwent colonoscopy with or without the assistance of AI (AI-C or conventional colonoscopy (CC)). Examinations were performed with two different AI systems, that is, Fujifilm CADEye and Medtronic GI Genius. The primary outcome was ADR. RESULTS: Among 286 patients, 240 underwent analysis (average age: 66 years). The ADR was 42% for all patients, and no significant difference emerged between AI-C and CC groups (41% vs 43%). The overall PDR was 61%, with a trend towards higher PDR in the AI-C group. Subgroup analysis revealed higher detection rates for sessile serrated lesions (SSL) with AI assistance (AI-C 22%, CC 11%, p=0.004). No difference was noticed in the detection of polyps or adenomas per colonoscopy. Examinations were most often performed by experienced endoscopists, 78% (n=86 AI-C, 100 CC). CONCLUSION: Amidst the ongoing AI integration, ADR did not improve with AI. Particularly noteworthy is the enhanced detection rates for SSL by AI assistance, especially since they pose a risk for postcolonoscopy CRC. The integration of AI into standard colonoscopy practice warrants further investigation and the development of improved software might be necessary before enforcing its mandatory implementation. TRIAL REGISTRATION NUMBER: NCT05178095.
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Adenoma , Inteligencia Artificial , Humanos , Anciano , Estudios Prospectivos , Detección Precoz del Cáncer , Colonoscopía , Adenoma/patologíaRESUMEN
BACKGROUND: Radiotherapy is effective in the treatment of cancer but also causes damage to non-cancerous tissue. Pelvic radiotherapy may produce chronic and debilitating bowel symptoms, yet the underlying pathophysiology is still undefined. Most notably, although pelvic radiotherapy causes an acute intestinal inflammation there is no consensus on whether the late-phase pathophysiology contains an inflammatory component or not. To address this knowledge gap, we examined the potential presence of a chronic inflammation in mucosal biopsies from irradiated pelvic cancer survivors. METHODS: We biopsied 24 cancer survivors two to 20 years after pelvic radiotherapy, and four non-irradiated controls. Using tandem mass tag (TMT) mass spectrometry and mRNA sequencing (mRNA-seq), we charted proteomic and transcriptomic profiles of the mucosal tissue previously exposed to a high or a low/no dose of radiation. Changes in the immune cell populations were determined with flow cytometry. The integrity of the protective mucus layers were determined by permeability analysis and 16S rRNA bacterial detection. FINDINGS: 942 proteins were differentially expressed in mucosa previously exposed to a high radiation dose compared to a low radiation dose. The data suggested a chronic low-grade inflammation with neutrophil activity, which was confirmed by mRNA-seq and flow cytometry and further supported by findings of a weakened mucus barrier with bacterial infiltration. INTERPRETATION: Our results challenge the idea that pelvic radiotherapy causes an acute intestinal inflammation that either heals or turns fibrotic without progression to chronic inflammation. This provides a rationale for exploring novel strategies to mitigate chronic bowel symptoms in pelvic cancer survivors. FUNDING: This study was supported by the King Gustav V Jubilee Clinic Cancer Foundation (CB), The Adlerbertska Research Foundation (CB), The Swedish Cancer Society (GS), The Swedish State under the ALF agreement (GS and CB), Mary von Sydow's foundation (MA and VP).
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Pacientes Ambulatorios , Dolor , Humanos , Reproducibilidad de los Resultados , Factores de RiesgoRESUMEN
BACKGROUND: The gastrointestinal tract is the second most involved organ for graft-versus-host disease where involvement of the small intestine is present in 50% of the cases. Therefore, the use of a non-invasive investigation i.e., video capsule endoscopy (VCE) seems ideal in the diagnostic work-up, but this has never been systematically evaluated before. OBJECTIVE: The aim of this systematic review was to determine the efficacy and safety of VCE, in comparison with conventional endoscopy in patients who received hematopoietic stem cell transplantation. METHOD: Databases searched were PubMed, Scopus, EMBASE, and Cochrane CENTRAL. All databases were searched from their inception date until June 17, 2022. The search identified 792 publications, of which 8 studies were included in our analysis comprising of 232 unique patients. Efficacy was calculated in comparison with the golden standard i.e., histology. Risk of bias assessment was performed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. RESULTS: The pooled sensitivity was higher for VCE at 0.77 (95% CI: 0.60-0.89) compared to conventional endoscopy 0.62 (95% CI: 0.47-0.75) but the difference was not statistically significant (p = 0.155, Q = 2.02). Similarly, the pooled specificity was higher for VCE at 0.68 (95% CI: 0.46-0.84) than for conventional endoscopy at 0.58 (95% CI: 0.40-0.74) but not statistically significant (p = 0.457, Q = 0.55). Moreover, concern for adverse events such as intestinal obstruction or perforation was not justified since none of the capsules were retained in the small bowel and no perforations occurred in relation to VCE. A limitation to the study is the retrospective approach seen in 50% of the studies. CONCLUSION: The role of video capsule endoscopy in diagnosing or dismissing graft-versus-host disease is not yet established and requires further studies. However, the modality appears safe in this cohort.
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Endoscopía Capsular , Enfermedad Injerto contra Huésped , Humanos , Endoscopía Capsular/efectos adversos , Estudios Retrospectivos , Tracto Gastrointestinal , Intestino Delgado/patología , Enfermedad Injerto contra Huésped/diagnóstico , Enfermedad Injerto contra Huésped/etiología , Enfermedad Injerto contra Huésped/patología , Hemorragia Gastrointestinal/etiología , Endoscopía GastrointestinalRESUMEN
Background: Insulinoma is a rare pancreatic neuroendocrine neoplasm with an incidence of 0.7-4 cases per million/year. Because of its rarity, epidemiological studies on insulinoma are few and limited by small sample sizes. An increasing incidence of insulinoma has recently been suggested. The primary aim of this study was to investigate the incidence of insulinoma in the Västra Götaland Region (VGR) of Sweden. Secondary aims were to evaluate clinical characteristics, diagnostic workup, management and outcome in patients diagnosed with insulinoma. Methods: Medical records were reviewed for all patients in the VGR who had received an ICD-10 diagnosis code of a benign (D13.7) and/or a malignant (C25.4) tumor in the endocrine part of the pancreas, of hypoglycemia (E.161), and/or a code of a fasting test (AB011), from 2002-2019. Results: Forty-two patients with insulinoma were identified, 37 of whom (20 men) were residents in the VGR at the time of diagnosis, giving a mean annual incidence of 1.3 cases per million/year. The mean (±standard deviation) age at diagnosis was 56±18 years. Six of the 37 (16%) patients had metastatic insulinoma and 2 patients (5%) had a confirmed multiple endocrine neoplasia type 1 syndrome. At preoperative workup, computed tomography and endoscopic ultrasound detected an insulinoma in 28/36 (78%) and 21/21 (100%) cases, respectively. Conclusions: Insulinoma remains a rare tumor in the modern era. The recorded mean annual incidence of 1.3 cases per million/year is compatible with the reported incidence in Sweden during the 1980s. Our results do not support an increasing incidence of insulinoma.
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Accurate pretreatment grading of pancreatic neuroendocrine tumors (PanNETs) is important to guide patient management. We aimed to evaluate endoscopic ultrasound-guided fine needle biopsy sampling (EUS-FNB) for the preoperative diagnosis and grading of PanNETs. In a tertiary-center setting, patients with suspected PanNETs were prospectively subjected to 22-gauge, reverse-bevel EUS-FNB. The EUS-FNB samples (Ki-67EUS) and corresponding surgical specimens (Ki-67SURG) were analyzed with Ki-67 indexing and thereafter tumor grading, (GRADEEUS) and (GRADESURG) respectively. In total 52 PanNET-patients [median age: 66 years; females: 25/52; surgical resection 22/52 (42%)] were included. EUS-FNB was diagnostic in 44/52 (85%). In 42 available FNB-slides, the median neoplastic cell count was 1034 (IQR: 504-3667) with 32/42 (76%), 22/42 (52%), and 14/42 (33%) cases exceeding 500, 1000, and 2000 neoplastic cells respectively. Ki-67SURG was significantly higher compared to Ki-67EUS with a moderate correlation comparing Ki-67EUS and Ki-67SURG (Pearson r = 0.60, r2 = 0.36, p = 0.011). The GRADEEUS had a weak level of agreement (κ = 0.08) compared with GRADESURG. Only 2/12 (17%) G2-tumors were correctly graded in EUS-FNB-samples. EUS-guided fine needle biopsy sampling is sensitive for preoperative diagnosis of PanNET but biopsy quality is relatively poor. Therefore, the approach seems suboptimal for pretreatment grading of PanNET.
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Biopsia por Aspiración con Aguja Fina Guiada por Ultrasonido Endoscópico , Tumores Neuroendocrinos , Neoplasias Pancreáticas , Anciano , Femenino , Humanos , Antígeno Ki-67/análisis , Masculino , Clasificación del Tumor , Tumores Neuroendocrinos/diagnóstico por imagen , Tumores Neuroendocrinos/patología , Neoplasias Pancreáticas/diagnóstico por imagen , Neoplasias Pancreáticas/patología , Estudios ProspectivosRESUMEN
BACKGROUND: Adequate management of patient pain and discomfort during colonoscopy is crucial to obtaining a high-quality examination. We aimed to investigate the ability of endoscopists and endoscopy assistants to accurately assess patient pain in colonoscopy. METHODS: This was a single-center, cross-sectional study including patients scheduled for an outpatient colonoscopy. Procedure-related pain, as experienced by the patient, was scored on a verbal rating scale (VRS). Endoscopists and endoscopy assistants rated patient pain likewise. Cohen's kappa was used to measure the agreement between ratings and logistic regression applied to test for potential predictors associated with underestimation of moderate-severe pain. RESULTS: In total, 785 patients [median age: 54 years; females: n = 413] were included. Mild, moderate, and severe pain was reported in 378/785 (48%), 168/785 (22%), and 111/785 (14%) procedures respectively. Inter-rater reliability of patient pain comparing patients with endoscopists was κ = 0.29, p < .001 and for patients with endoscopy assistants κ = 0.37, p < .001. In the 279 patients reporting moderate/severe pain, multivariable analysis showed that male gender (OR = 1.79), normal BMI (OR = 1.71), no history of abdominal surgery (OR = 1.81), and index-colonoscopy (OR = 1.81) were factors significantly associated with a risk for underestimation of moderate/severe pain by endoscopists. Young age (OR = 2.05) was the only corresponding factor valid for endoscopy assistants. CONCLUSIONS: In a colonoscopy, estimation of patient pain by endoscopists and endoscopy assistants is often inaccurate. Endoscopists need to pay specific attention to subgroups of patients, such as male gender, and normal BMI, among whom there seems to be an important risk of underestimation of moderate-severe pain.
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Colonoscopía , Pacientes Ambulatorios , Colonoscopía/efectos adversos , Colonoscopía/métodos , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dolor/diagnóstico , Dolor/etiología , Reproducibilidad de los Resultados , Factores de RiesgoRESUMEN
OBJECTIVE: Chronic rejection (CR) of the small intestinal allograft includes mucosal fibrosis, bowel thickening and arteriopathy in the outer wall layers and the mesentery. CR lacks non-invasive markers and reliable diagnostic methods. We evaluated endoscopic ultrasound (EUS) as a novel approach for monitoring of the intestinal allograft with respect to CR. DESIGN: In intestinal graft recipients, EUS and enteroscopy with ileal mucosal biopsy were performed via the ileostomy. At EUS, the wall thickness of the intestinal graft was measured in standard mode, whereas the resistive index (RI) of the supplying artery was assessed in pulsed Doppler mode. At enteroscopy, the intestinal mucosa was assessed. Findings were compared with histopathology and clinical follow-up. RESULTS: EUS was successfully performed in all 11 patients (adequate clinical course (AC) n=9; CR n=2) after a median interval of 1537 days (range: 170-5204), post-transplantation. The total diameter of the wall (layer I-V) was comparable in all patients. Meanwhile, the diameter of the outermost part (layer IV-V; that is, muscularis propria-serosa) was among the two CR patients (range: 1.3-1.4 mm) in the upper end of measurements as compared with the nine AC patients (range: 0.5-1.4 mm). The RI was >0.9 in both CR patients, while the RI was ≤0.8 in all AC patients. Both CR patients had abnormal findings at enteroscopy and histopathology and deceased during follow-up. CONCLUSION: EUS is a promising tool providing detailed information on the intestinal graft morphology and rheology, which may be used for assessment of potential CR in long-term follow-up of intestinal allograft recipients.
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Endosonografía , Intestino Delgado , Aloinjertos , Humanos , Mucosa Intestinal/diagnóstico por imagen , Mucosa Intestinal/patología , Intestino Delgado/patología , Trasplante Homólogo/efectos adversosRESUMEN
We present a case of a 41-year-old woman who visited the emergency department (ED) with acute abdomen. She was diagnosed with perforated appendicitis and abscess formation on CT. She was treated conservatively with antibiotics and discharged. On control CT 3 months later, the appendix had healed, but signs of thickening of the terminal ileum were noticed and colonoscopy was performed, which was uneventful and showed no signs of inflammation. Twelve hours later, she developed pain in the right lower quadrant, followed by fever, and visited the ED. Physical examination and blood work showed signs consistent with acute appendicitis, and appendectomy was performed laparoscopically 6 hours later. The patient recovered remarkably shortly afterwards. Whether colonoscopy resulted in de novo appendicitis or exacerbated an already existing inflammation remains unknown. However, endoscopists should be aware of this rare, yet serious complication and consider it in the workup of post-colonoscopy abdominal pain.
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Apendicitis , Apéndice , Dolor Abdominal/etiología , Adulto , Apendicectomía/efectos adversos , Apendicitis/diagnóstico por imagen , Apendicitis/cirugía , Colonoscopía , Femenino , HumanosRESUMEN
OBJECTIVE: Endosonography (EUS) is a useful but complex diagnostic modality which requires advanced endoscopy training and guidance by a supervisor. Since learning curves vary among individuals, assessment of the actual competence among EUS trainees is important. DESIGN/METHODS: We designed a novel assessment tool entitled Global Assessment of Performance and Skills in EUS (GAPS-EUS) for assessing skills among EUS trainees. Five quality indicators were marked on a five-grade scale by the supervisor (Observer Score) and by the trainee (Trainee Score). Trainees were included in two high-volume centres (Gothenburg, Sweden, and Bologna, Italy). Outcomes were feasibility, patient safety, reliability, and validity of GAPS-EUS in trainee-performed EUS procedures. RESULTS: Twenty-two EUS-trainees were assessed in a total of 157 EUS procedures with a completion rate of 157/157 (100 %) and a patient adverse event rate of 2/157 (1.3 %; gastroenteritis n=1, fever n=1). GAPS-EUS showed a high measurement reliability (Cronbach's alpha coefficient=0.87) and a high inter-rater reliability comparing the supervisor and the trainee (r=0.83, r2=0.69, p<0.001). The construct of GAPS-EUS was verified by comparing low-level and high-level performance procedures and the content validity by recording that the EUS-FNA manoeuvre resulted in a lower score than other aspects of EUS 3.07 (95% CI 2.91 to 3.23) vs 3.51 (95% CI 3.37 to 3.65) (p<0.001). External validity was confirmed via similar findings in both centres. CONCLUSION: GAPS-EUS is an easy-to-use and reliable tool with a recorded high validity for the assessment of competence among trainees in EUS. It can be recommended to centres involved in the education of future endosonographers. TRIAL REGISTRATION NUMBER: NCT02455570.
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Competencia Clínica , Endosonografía , Humanos , Curva de Aprendizaje , Estudios Prospectivos , Reproducibilidad de los ResultadosRESUMEN
Hepatic encephalopathy (HE) is a frequent complication of liver cirrhosis, which is mostly characterized by psychomotor slowing. However, psychotic symptoms such as visual and olfactory hallucinations may sometimes also be present. In contrast, auditory hallucinations are uncommon in chronic liver disease. In this case report, we present a patient with liver cirrhosis due to excessive alcohol consumption who presented to the emergency department with disorientation and signs of infection. Initial assessment led to the diagnosis acute on chronic liver failure exacerbated by infection leading to encephalopathy. The patient was admitted and successfully treated with antibiotics, Lactulose and Rifaximin. Gastroscopy showed varices without bleeding stigmata and Propranolol 20 mg was initiated as primary prophylaxis. Upon follow-up, the patient was clinically stable but had developed visual and auditory hallucinations which raised the suspicion that HE was not the cause. CT scan of the brain was unremarkable and the hallucinations were considered to be caused by Propranolol and disappeared shortly after switching to Carvedilol.
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Encefalopatía Hepática , Propranolol , Alucinaciones/inducido químicamente , Alucinaciones/tratamiento farmacológico , Encefalopatía Hepática/inducido químicamente , Encefalopatía Hepática/diagnóstico , Encefalopatía Hepática/tratamiento farmacológico , Humanos , Cirrosis Hepática/complicaciones , Propranolol/uso terapéutico , RifaximinaRESUMEN
OBJECTIVE: Fibrotic strictures in the gastrointestinal tract are frequent in Crohn's disease. Endoscopic dilation is a standard treatment. However, recurrence is common after dilation and there are complications such as bleeding or perforation. Endoscopic treatment using self-expandable metal stents has shown diverging results. The aim of this study was to evaluate the outcome of endoscopic treatment with a self-expandable stent in ileocecal Crohn's disease. DESIGN/METHOD: Patients with Crohn's disease and a symptomatic ileocecal stricture were eligible for prospective, consecutive inclusion in a single-centre setting. Patients were randomised to treatment with either 18 mm balloon dilatation (GroupDIL) or stenting (GroupSTENT) using a 20 mm diameter, partially covered Hanarostent NCN. Patients were followed for a minimum of 24 months postendoscopy. Outcomes were technical success, adverse events and clinical success (defined as no need for repeated interventions). RESULTS: Thirteen patients (GroupDIL n=6; GroupSTENT=7) were included with twelve patients (GroupDIL n=5; GroupSTENT=7) being eligible for complete follow-up. Technical success was achieved in all cases. Adverse events were border-line significantly more common in the GroupSTENT: 4/7 (57%) (pain: n=3; pain and rectal bleeding: n=1) compared with the GroupDIL: 0/5 (0%), p=0.08, which resulted in preterm termination of the study. The clinical success rate was GroupSTENT: 6/7 (86%) vs GroupDIL: 1/5 (20%), p=0.07. CONCLUSION: Patients with strictures related to Crohn's disease may benefit from treatment with self-expandable metal stents rather than dilatation. However, there seems to be an increased risk for patient pain after stenting, which has to be considered and handled. TRAIL REGISTRATION NUMBER: The study was registered at Clinical Trials (NCT04718493).
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Stents , Constricción Patológica/etiología , Dilatación , Humanos , Recién Nacido , Estudios Prospectivos , Estudios Retrospectivos , Stents/efectos adversos , Resultado del TratamientoRESUMEN
BACKGROUND/AIMS: The diagnostic work-up of lymphadenopathy is challenging but important to determine the correct therapy. Nevertheless, few studies have addressed the topic of endosonography (EUS)-guided tissue acquisition in lymphadenopathy. Therefore, we aimed to evaluate the accuracy and safety of EUS-guided fine-needle biopsy sampling (EUS-FNB) in intrathoracic and intraabdominal lymphadenopathy. METHODS: In a tertiary care center, patients with lymphadenopathy referred for EUS-guided sampling were included prospectively from 2014 to 2019 (NCT02360839). In all cases, EUS-FNB (22 gauge) and EUS-guided fine-needle aspiration (EUS-FNA) (25 gauge) were performed. The patients were randomized to the first needle pass with FNB or FNA. Study outcomes were the diagnostic accuracy and adverse event rate. RESULTS: Forty-eight patients were included (median age: 69 years [interquartile range, 59-76]; 24/48 females [50%]). The final diagnoses were metastasis (n=17), lymphoma (n=11), sarcoidosis (n=6), and inflammatory disease (n=14). The diagnostic performance of the two modalities was comparable, including a high sensitivity for metastatic nodes (EUS-FNB: 87% vs. EUSFNA: 100%, p=0.5). The sensitivity for lymphoma was borderline superior in favor of EUS-FNB (EUS-FNB: 55% vs. EUS-FNA: 9%, p=0.06). No adverse events were recorded. CONCLUSION: In lymphadenopathy, both EUS-FNB and EUS-FNA are safe and highly sensitive for metastatic lymph node detection. Lymphoma diagnosis is challenging regardless of the needle used.
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BACKGROUND: Neoadjuvant tyrosine kinase inhibitor (TKI) therapy increases the chance of organ-preserving, radical resection in selected patients with gastrointestinal stromal tumors (GISTs). We aimed to evaluate systematic, immediate DNA sequencing of KIT and PDGFRA in pretreatment GIST tissue to guide neoadjuvant TKI therapy and optimize preoperative tumor response. METHODS: All patients who were candidates for neoadjuvant therapy of a suspected GIST [the study cohort (SC)] were prospectively included from January 2014 to March 2018. Patients were subjected to pretreatment endosonography-guided fine-needle biopsy (EUS-FNB) or transabdominal ultrasound-guided needle biopsy (TUS-NB), followed by immediate tumor DNA sequencing (< 2 weeks). A historic (2006-2013) reference cohort (RC) underwent work-up without sequencing before neoadjuvant imatinib (n = 42). The rate of optimal neoadjuvant therapy (TherapyOPTIMAL) was calculated, and the induced tumor size reduction (Tumor RegressionMAX, %) was evaluated by computed tomography (CT) scan. RESULTS: The success rate of pretreatment tumor DNA sequencing in the SC (n = 81) was 77/81 (95%) [EUS-FNB 71/74 (96%); TUS-NB 6/7 (86%)], with mutations localized in KIT (n = 58), PDGFRA (n = 18), or neither gene, wild type (n = 5). In patients with a final indication for neoadjuvant therapy, the TherapyOPTIMAL was higher in the SC compared with the RC [61/63 (97%) versus 33/42 (79%), p = 0.006], leading to a significantly higher Tumor RegressionMAX in patients treated with TKI (27% vs. 19%, p = 0.015). CONCLUSIONS: Pretreatment endosonography-guided biopsy sampling followed by immediate tumor DNA sequencing of KIT and PDGFRA is highly accurate and valuable in guiding neoadjuvant TKI therapy in GIST. This approach minimizes maltreatment with inappropriate regimens and leads to improved tumor size reduction before surgery.