Emerging Diagnostic Indications for Endoscopic Ultrasound.

Endoscopic ultrasound (EUS) has evolved from a diagnostic imaging tool into a versatile platform that enables high-precision access, sampling, and therapy across gastrointestinal and hepatobiliary diseases. This review summarizes recent advances that are reshaping diagnostic practice and theragnostics. In chronic pancreatitis, EUS remains central when cross-sectional imaging is equivocal; secretin-stimulated endoscopic pancreatic function testing can complement morphology, although discordant results limit standalone certainty. For pancreatic cancer, secretin-stimulated duodenal pancreatic-juice collection enables "liquid biopsy" analyses-including methylated DNA markers and extracellular-vesicle microRNAs-that augment carbohydrate antigen 19-9 and may enhance early detection and cyst surveillance. In endohepatology, EUS-guided portal pressure gradient measurement and liver biopsy offer accurate, same-session assessment with strong safety profiles. Adjunctive imaging-contrast-enhanced EUS and elastography-improves lesion characterization and targeting. Tissue acquisition has shifted toward end-cutting fine-needle biopsy needles, optimized by fanning/torque techniques, wet-suction, and macroscopic/visual on-site evaluation, reducing passes while preserving molecular adequacy. Artificial intelligence is emerging across workflows-from differentiating pancreatic lesions and staging to automating standardized photodocumentation and reporting-and is being explored for needle-based confocal laser endomicroscopy image interpretation. For pancreatic cysts, glucose, selected genomics (eg, KRAS/GNAS and targeted panels), and through-the-needle biopsy refine diagnosis. Finally, EUS-obtained tissue now seeds organoids, patient-derived xenografts, and organotypic slice cultures to test individualized therapies. Collectively, these innovations move EUS beyond "see and biopsy" toward detect, predict, and personalize.