This is a single center experience of 23 EUS examinations in 20 patients for mediastinal masses of unknown origin, suspected mediastinal cysts or follow up of a known cyst. In 19 patients, the definite diagnosis of a mediastinal cyst was established by EUS. In three cases, the cyst contents were aspirated by EUS-FNA. EUS-FNA in a fourth case of solid appearing duplication cyst resulted in severe sepsis secondary to mediastinitis with thoracotomy revealing an infected bronchogenic cyst.

EUS imaging is a useful technique for further diagnostic characterization of mediastinal cysts. However, as shown by the authors, one should resist the temptation of performing EUS-FNA in these patients due to risk of an infectious complication. This complication would be even more significant when the patient with a mediastinal cyst is asymptomatic and the cyst is incidentally discovered (a not so uncommon scenario). Thus, EUS-FNA in these lesions should be performed when the additional information from FNA is clearly going to assist in clinical decision making.

The aim of this study was to report the sensitivity, cytological diagnoses, EUS features, complications, clinical impact, and long term clinical follow up of a single center experience with EUS-FNA of benign and malignant solid liver lesions in 77 patients. Depending on the status of unclassified lesions, the sensitivity of EUS-FNA for the diagnosis of malignancy ranged from 82% to 94%. EUS detected malignancy in 41% of patients with previously negative examinations. For the 45 subjects with cytology positive for malignancy, EUS-FNA changed management in 86% of patients.

This study adds to the increasing reports of EUS-FNA in liver lesions and shows that this appears to be an area where EUS can have significant clinical impact. However, since liver lesions are easily approachable by interventional radiology via the percutaneous route, the application of EUS for liver lesions at a particular institution may be dependent on the quality and expertise of interventional radiologists as well the quality of the CT/MRI scanners. As the authors have correctly pointed out, comparative studies between EUS-FNA and percutaneous FNA/biopsy with the regards to accuracy and complications are needed. At the current level of knowledge, decision to perform EUS-FNA for solid liver lesion (and its sequence in comparison to percutaneous FNA or other imaging tests) should be done on a case to case basis depending on the institutional expertise and the clinical situation.

This is a review paper in the Expert Approach Section of the journal Endoscopy. The aim of the expert approach section is to contribute to the dissemination and standardization of new endoscopic procedures. Authors from three distinct geographic areas combine forces, sharing their experience to form a consensus of opinion. The paper reviews the basic principles of EUS guided cystogastrostomy as well the echoendoscopes and accessories needed to get the job done. The procedure is described in a step by step fashion with good figures. Literature and success rate in 79 published cases of EUS guided pancreatic pseudocyst drainage is nicely tabulated and cross referenced. This is a nice technical review for endoscopists interested in this technique.