Introduction.

Endoscopic ultrasound (EUS) was born from the combination of a high-frequency ultrasound probe with an endoscope to assess in detail the walls of the upper and lower gastrointestinal tract and surrounding organs and structures. The subsequent possibility of EUS-guided tissue acquisition has rapidly established the irreplaceable role of EUS in the management of a wide range of benign and malignant gastrointestinal diseases. The actual diagnostic armamentarium involving fine-Doppler, elastography, and contrast enhancement has significantly improved its diagnostic yield, which could be even more refined by newer ways of interrogating data and images, such as artificial intelligence. Technological development (e.g., new echendoscopes, larger operative channels, special-design needles, lumen apposing metal stents, and dedicated biliary stents) and the clinical need for new, more effective, and less-invasive procedures has rapidly evolved EUS from a purely diagnostic tool to a therapeutic modality, that is making increasingly outdated some surgical or radiological procedures that have hitherto been considered standard of care.