Question

Role of EUS in the diagnosis of GIST.

Hint:

EUS is an essential tool in diagnosing GISTs and assessing their depth of invasion, guiding treatment decisions.

Answer 1

Endoscopic ultrasound (EUS) is a valuable imaging tool for diagnosing and staging gastrointestinal stromal tumors (GISTs), particularly for lesions located in the wall of the gastrointestinal tract.
Step 1: Mechanism of EUS:
1. High-Resolution Imaging: EUS provides high-resolution images of the gastrointestinal wall and surrounding tissues, making it effective for detecting small GISTs.
2. Evaluation of Tumor Size and Depth: EUS can assess the size of the tumor and determine whether it involves the layers of the gastrointestinal wall, which is crucial for staging.
Step 2: Clinical Use of EUS in GIST:
1. Diagnosis and Biopsy: EUS-guided fine needle aspiration (FN allows for the collection of tissue samples for histological diagnosis.
2. Staging and Risk Assessment: EUS is helpful in assessing the depth of tumor invasion, which is important for determining the risk of metastasis and planning treatment.