Endoscopic ultrasonography for gastric submucosal lesions

Abstract

Gastric submucosal tumors (SMTs) are a rather frequent finding, occurring in about 0.36% of routine upper GI-endoscopies. EUS has emerged as a reliable investigative procedure for evaluation of these lesions. Diagnostic Endoscopic ultrasonography (EUS) has the ability to differentiate intramural tumors from extraluminal compressions and can also show the layer of origin of gastric SMTs. Tumors can be further characterized by their layer of origin, echo pattern and margin. EUS-risk criteria of their malignant potential are presented, although the emergence of EUS-guided fne needle aspiration (EUS-FNA) has opened new indications for transmural tissue diagnosis and expanded the possibilities of EUS in SMTs of the stomach. Tissue diagnosis should address whether the SMT is a Gastrointestinal stromal tumour (GIST) or another tumor type and evaluate the malignant potential of a given GIST. However, there seems to be a lack of data on the optimal strategy in SMTs suspected to be GISTs with a negative EUS-FNA tissue diagnosis. The current management strategies, as well as open questions regarding their treatment are also presented.

Keywords: EUS-guided fne needle aspiration; Endoscopic ultrasound; Gastric submucosal tumors; Gastrointestinal stromal tumours.

Figure 1

Gastric endoscopic ultrasonography. Note the 5 distinct layers that comprise the gastric wall.

Figure 2

Gastric gastrointestinal stromal cell tumors: Endoscopic aspects, endoscopic ultrasonography-imaging and tissue sampling. A: Endoscopic image of the lesion; note that the lesion is covered by a normal mucosa with a central umbilication (black arrow); B: EUS imaging of the lesion, which is located in the 4th echo-poor layer (muscularis propria); C: EUS-FNA of the lesion; note the presence of the needle (white arrow); D: Histological specimen of the EUS-FNA. EUS:Endoscopic ultrasonography; EUS-FNA: EUS-guided fne needle aspiration.

Figure 3

Pancreatic rest of the stomach: Endoscopic and endoscopic ultrasonography -imaging. A: Endoscopic image of a pancreatic rest. Note the duct opening on the surface of lesion is covered by a normal mucosa with a central umbilication (arrow); B: EUS imaging of the lesion which originates from the 3rd layer, i.e. the submucosa (arrow); note the lesion’s mixed echogenicity. EUS: Endoscopic ultrasonography.

Figure 4

Duplication cyst of the stomach. A: Endoscopic image of the lesion (retrograde view); B: EUS imaging of the same lesion; note the lesion’s 3-layer structure which originates from the 3rd layer, i.e. the submucosa (arrow). EUS: Endoscopic ultrasonography.

Figure 5

Gastric varices in endoscopy and endoscopic ultrasonography. A, B: Endoscopic image of gastric varices presenting as thick serpiginous structures, covered by normal mucosa; C: EUS imaging of the varices; note their tortuous, anechoic structure which originates from the 3rd layer, i.e. the submucosa (arrow); D: EUS Doppler imaging of the same varices; the positive signal denotes their vascular origin. EUS: Endoscopic ultrasonography.