Multimodal endoscopic ultrasound can help to differentiate between benign (non-cancerous) and malignant (cancerous) causes of thickening of the upper digestive tract wall.

The main questions this study aims to answer are:

How accurate is multimodal endoscopic ultrasound in identifying the cause of upper digestive tract wall thickening?

Can using several ultrasound techniques together improve diagnosis when standard tests are unclear?

Participants are adults who have upper digestive tract wall thickening seen on scans such as computed tomography (CT) or magnetic resonance imaging (MRI).

Participants will:

Undergo upper endoscopy followed by endoscopic ultrasound and tissue sample taken during the procedure when needed followed by using biopsy results or clinical follow-up to confirm the final diagnosis

This study aims to improve early and accurate diagnosis and help guide proper treatment decisions for people with unexplained upper digestive tract wall thickening.

Upper gastrointestinal wall thickening (UGIT) refers to the abnormal increase in the thickness of the gastrointestinal wall, which can be observed in various clinical conditions, including both benign and malignant diseases (1).

Abnormal gastric wall thickening can be caused by a wide range of benign and malignant conditions, and expedient diagnosis is required to commence the appropriate treatment (2, 3).

Traditional diagnostic approaches for evaluating UGIT rely primarily on cross-sectional imaging techniques such as contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI). However, these modalities often lack sufficient spatial resolution to accurately characterize the individual layers of the gastrointestinal wall, particularly in cases of subtle mucosal or submucosal disease (4, 5).

Esophagogastroduodenoscopy (EGD) allows direct visualization of the mucosal surface and enables tissue sampling through conventional biopsies. Nevertheless, many pathological processes responsible for gastrointestinal wall thickening-such as gastric lymphoma, subepithelial tumors, linitis plastica, and infiltrative scirrhous carcinoma-originate in the deeper layers of the gastrointestinal wall (6).

EUS allows clear delineation of the gastrointestinal wall layers and surrounding structures. EUS-guided tissue acquisition using fine-needle biopsy (FNB) allows sampling of submucosal and muscular lesions that are inaccessible to conventional endoscopic biopsies (1).

Inclusion Criteria:

• Age ≥18 years
• Patients with endoscopic or radiological (U/S, CT or MRI) evidence of upper GI wall thickening (esophagus, stomach, or duodenum) and defined based on established radiologic standards. A wall thickness by MSCT >5 mm in the oesophagus and stomach and >4 mm in the duodenum in accordance with accepted CT imaging criteria (4, 7).
• Written informed consent provided.

Exclusion Criteria:

• Patient refusal or inability to provide informed consent
• Uncorrectable coagulation disorder e.g prothrombin concentration <60%, INR >1.5 or platelet count <50,000/µL that cannot be corrected pre-procedure according to institutional guidelines.
• Presence of contraindications for endoscopy/sedation.
• Known diagnosis explaining wall thickening prior to EUS.

Patients with endoscopic or radiological (U/S, CT or MRI) evidence of upper GI wall thickening (esophagus, stomach, or duodenum) and defined based on established radiologic standards. A wall thickness by MSCT >5 mm in the oesophagus and stomach and >4 mm in the duodenum in accordance with accepted CT imaging criteria