Endoscopic Ultrasound

**73**

**Chapter 5**

Lesions

**Abstract**

**1. Introduction**

Endoscopic Ultrasound

endoscopic characteristics of a cyst or a lipoma.

duodenum, endoscopy, interventional endoscopy

*Andrada Seicean, Voicu Rednic and Radu Seicean*

Assessment of the Duodenal Wall

Subepithelial tumors (SETs) in the upper digestive tract are rare and only 10% of are located in the duodenum. Assessment of lesions protruding from the duodenal wall is difficult. Upper gastrointestinal (GI) endoscopy and computed tomography (CT) are not able to completely distinguish between different tumors and guide their subsequent management. Endoscopic ultrasonography (EUS) has a significant diagnostic yield in this context. EUS is able to accurately diagnose duodenal lesions, perform a biopsy if considered useful, guide the approach for resection and provide appropriate follow-up. SETs reported during upper GI endoscopy are more commonly cysts, polyps, lipomas, Brunner's gland adenoma, ectopic pancreas, gastrointestinal stromal tumors (GISTs) or neuroendocrine tumors (NETs). In addition, although more rarely, adenocarcinomas and lymphomas can be identified. EUS should be performed for any duodenal lesion larger than 1 cm that lacks the

**Keywords:** subepithelial tumors, intramural lesions, endoscopic ultrasound,

lack the resolution to properly describe them because of their size.

EUS is the most effective for evaluating SETs of the duodenum.

Lesions of the upper gastrointestinal (GI) tract are usually assessed by esophagogastroduodenoscopy (EGD), but less importance is shown for lesions of the small intestine. Protrusive lesions of the small intestine can arise from mucosa, with endoscopic features that allow their characterization. However, deep organ involvement cannot be assessed by endoscopy. The same is true for lesions from subepithelial layers, known as subepithelial lesions (SELs). These appear as bulging lesions covered by normal mucosa, and are firm as they are "palpated" with closed biopsy forceps. The mucosa covering these lesions is usually normal, and standard biopsies or "bite-to-bite" biopsies have low diagnostic accuracy. Assessing these lesions can be difficult, as computed tomography (CT) and magnetic resonance imaging (MRI)

Endoscopic ultrasound (EUS) overcomes these drawbacks. Due to high resolution and ability to differentiate between all layers of the GI tract [1], EUS assesses the layer of origin, size, morphologic features, and involvement of the neighboring organs. Combined with the possibility of targeted biopsies from the deeper layers,
