ABSTRACT
The pancreatoduodenal groove is a small area where pathologic processes involving the distal bile duct, duodenum, pancreatic head, ampulla of Vater, and retroperitoneum converge. Despite great advances in imaging techniques, a definitive preoperative diagnosis is challenging because of the complex anatomy of this area. Therefore, surgical intervention is frequently required because of the inability to completely exclude malignancy. We report 3 cases of patients with different groove pathologies but similar clinical and imaging presentation, and show the essential role of endoscopic ultrasound (EUS) in making a specific preoperative diagnosis, excluding malignancy in the first case, changing diagnosis in the second case, and confirming malignancy in the third case. EUS was a fundamental tool in this cohort of patients, not only because of its ability to provide superior visualization of a difficult anatomical region, but because of the ability to guide precise, real-time procedures, such as fine-needle aspiration.