Endoscopic ultrasonography: equipment and technique

Endoscopic ultrasonography for gastric submucosal lesions

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.

Endoscopic ultrasonography for gastric submucosal lesions

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.

Role of endoscopic ultrasound in the diagnosis and staging of pancreatic cancer

Early diagnosis of pancreatic cancer remains a difficult task, and multiple imaging tests have been proposed over the years. The aim of this review is to describe the current role of endoscopic ultrasound (EUS) for the diagnosis and staging of patients with pancreatic cancer. A detailed search of MEDLINE between 1980 and 2007 was performed using the following keywords: pancreatic cancer, endoscopic ultrasound, diagnosis, and staging. References of the selected articles were also browsed and consulted. Despite progress made with other imaging methods, EUS is still considered to be superior for the detection of clinically suspected lesions, especially if the results of other cross-sectional imaging modalities are equivocal. The major advantage of EUS is the high negative predictive value that approaches 100%, indicating that the absence of a focal mass reliably excludes pancreatic cancer. The introduction of EUS-guided fine needle aspiration allows a preoperative diagnosis in patients with resectable cancer, as well as a confirmation of diagnosis before chemoradiotherapy for those that are not. This comprehensive review highlighted the diagnostic capabilities of EUS including the newest refinements such as contrast-enhanced EUS, EUS elastography, and 3-dimensional EUS. The place of EUS-guided biopsy is also emphasized, including the addition of molecular marker techniques.

Review of endoscopic ultrasound-guided fine-needle aspiration cytology

This review, based on the Hennepin County Medical Center experience and review of the literature, vastly covers the up-to-date role of endoscopic ultrasonography (EUS) and EUS-guided fine-needle aspiration (FNA) in evaluating tumorous lesions of the gastrointestinal tract and adjacent organs. Emphasis is given to the tumoral and nodal staging of esophageal, pulmonary, and pancreatic cancer. This review also discusses technical, pathological, and gastroenterologic aspects and the role of the pathologist and endosonographer in the evaluation of these lesions, as well as the corresponding FNA cytology and differential diagnosis.