Endoscopic ultrasound (EUS) is an advanced endoscopic technique currently used in the staging and diagnosis of many gastrointestinal neoplasms. The proximity of the echoendoscope to the gastrointestinal tract lends itself to a detailed view of the luminal pathology and the pancreas. This unique ability enables endoscopists to use EUS in patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Diagnostic EUS allows previously unidentified NETs to be localized. EUS also determines tumor management by staging the GEP-NETS, enabling the clinicians to choose the appropriate endoscopic or surgical management. The ability to obtain a tissue diagnosis with EUS guidance enables disease confirmation. Finally, recent developments suggest that EUS may be used to deliver therapeutic agents for the treatment of NETs. This review will highlight the advances in our knowledge of EUS in the clinical management of these tumors.
Carcinoid Tumor ; Gastrointestinal Neoplasms ; Gastrointestinal Tract ; Humans ; Neuroendocrine Tumors ; Pancreas ; Phenobarbital ; Stomach

Small bowel neuroendocrine tumors (NETs) represent approximately one-third of NETs of the gastrointestinal tract, and their incidence is increasing. When determining if endoscopic resection is appropriate, endoscopic ultrasound is used to assess the lesion size and depth of invasion for duodenal NETs. A number of techniques, including endoscopic mucosal resection (EMR), band-assisted EMR (band-EMR), endoscopic submucosal dissection (ESD), and over-the-scope clip-assisted endoscopic full-thickness resection (EFTR), have been studied; however, the best technique for endoscopic resection remains unclear. The vast majority of currently available data are retrospective, and prospective studies with longer follow-up times are required. For jejunal and ileal NETs, endoscopic techniques such as video capsule endoscopy (VCE) and balloon enteroscopy (BE) assist in diagnosis. This includes localization of the primary NET in metastatic disease where initial workup has been negative, and the identification of multifocal disease, which may change management and prognostication.

Pancreatic neuroendocrine tumors (PNETs) are relatively rare; however, the incidence has increased over the last few decades. They are classified as functional or non-functional tumors according to the presence of associated clinical symptoms. The majority are non-functional tumors. For classification and staging, the World Health Organization 2010 classification system is the most commonly accepted. Chromogranin A is the most sensitive marker but has insufficient specificity. In general, PNETs are hypervascular tumors, and multiphasic contrast-enhanced computed tomography is considered the first choice for imaging study. Multiphasic magnetic resonance imaging can detect PNETs smaller than 2 cm and small liver metastasis compared with other modalities. Somatostatin receptor scintigraphy is often used in cases where functional PNETs are suspected. Positron emission tomography (PET) scan with 18F-fluorodeoxyglucose cannot visualize PNETs, but PET with 68-Ga DOTATATE can. Endoscopic ultrasonography can characterize smaller PNETs using contrast and confirm histology through fine needle aspiration or biopsy. In this article, we review the characteristics of grading systems and diagnostic modalities commonly used for PNETs.
Biopsy ; Biopsy, Fine-Needle ; Chromogranin A ; Classification ; Diagnosis* ; Endosonography ; Incidence ; Liver ; Magnetic Resonance Imaging ; Neoplasm Metastasis ; Neuroectodermal Tumors, Primitive ; Neuroendocrine Tumors* ; Positron-Emission Tomography ; Radionuclide Imaging ; Receptors, Somatostatin ; Sensitivity and Specificity ; World Health Organization

Electronic health records (EHRs) have been increasingly adopted in clinical practices across the United States, providing a primary source of data for clinical research, particularly observational cohort studies. EHRs are a high-yield, low-maintenance source of longitudinal real-world data for large patient populations and provide a wealth of information and clinical contexts that are useful for clinical research and translation into practice. Despite these strengths, it is important to recognize the multiple limitations and challenges related to the use of EHR data in clinical research.Missing data are a major source of error and biases and can affect the representativeness of the cohort of interest, as well as the accuracy of the outcomes and exposures. Here, we aim to provide a critical understanding of the types of data available in EHRs and describe the impact of data heterogeneity, quality, and generalizability, which should be evaluated prior to and during the analysis of EHR data. We also identify challenges pertaining to data quality, including errors and biases, and examine potential sources of such biases and errors. Finally, we discuss approaches to mitigate and remediate these limitations. A proactive approach to addressing these issues can help ensure the integrity and quality of EHR data and the appropriateness of their use in clinical studies.

Background: The median-to-ulnar comparison test (MUCT), and increasingly, ultrasonography (US) are considered as complementary to and more sensitive than median nerve conduction study (NCS) in diagnosing carpal tunnel syndrome (CTS). Methods: In consecutive patients with hand paresthesia compatible with CTS but with normal median NCS, we additionally performed the MUCT and analyzed whether it yielded better diagnostic sensitivity. Results: In total, 163 hands of clinically diagnosed CTS patients were examined with routine NCS. The MUCT and US were performed in 81 hands and 31 hands, respectively. While median NCS was diagnostic in 85 (52.1%) hands, MUCT failed to demonstrate superior sensitivity over median NCS in the other hands and US revealed related abnormalities better than both routine NCS (p=0.006) and MUCT (p=0.002). Conclusions The MUCT offered no additional diagnostic benefit. On the other hand, sonographic examination had higher sensitivity for the diagnosis of CTS when applying several diagnostic criteria. Thus, US could be the screening test for diagnosing CTS prior to NCS with higher sensitivity than MUCT. However, further studies are needed to define the appropriate diagnostic criteria for US.

Background: The median-to-ulnar comparison test (MUCT), and increasingly, ultrasonography (US) are considered as complementary to and more sensitive than median nerve conduction study (NCS) in diagnosing carpal tunnel syndrome (CTS). Methods: In consecutive patients with hand paresthesia compatible with CTS but with normal median NCS, we additionally performed the MUCT and analyzed whether it yielded better diagnostic sensitivity. Results: In total, 163 hands of clinically diagnosed CTS patients were examined with routine NCS. The MUCT and US were performed in 81 hands and 31 hands, respectively. While median NCS was diagnostic in 85 (52.1%) hands, MUCT failed to demonstrate superior sensitivity over median NCS in the other hands and US revealed related abnormalities better than both routine NCS (p=0.006) and MUCT (p=0.002). Conclusions The MUCT offered no additional diagnostic benefit. On the other hand, sonographic examination had higher sensitivity for the diagnosis of CTS when applying several diagnostic criteria. Thus, US could be the screening test for diagnosing CTS prior to NCS with higher sensitivity than MUCT. However, further studies are needed to define the appropriate diagnostic criteria for US.