Endoscopic ultrasound (EUS)-guided fine needle aspiration has emerged as the procedure of choice to obtain samples to reach a definitive diagnosis of lesions of the gastrointestinal tract and of adjacent organs. The obtainment of a tissue core biopsy presents several advantages that can substantially contribute to the widespread diffusion of EUS utilization in the community and in countries where cytology expertise may be difficult to be achieved. This article will review the EUS-guided fine needle biopsy techniques developed so far, the clinical results, their limitations as well as their future perspective.

Endoscopic ultrasound (EUS) guided fine needle aspiration (FNA) is an established diagnostic tool in the management of pancreatic cystic lesions (PCLs). Due to the proximity to the target lesion, the fine diagnostic needle travels through only minimal normal tissues. The risks of bleeding, pancreatitis and infection are small. Valuable diagnostic morphological information can be obtained by EUS before the use of FNA. The additional cytopathologic and cyst fluid analysis for the conventional markers such as amylase, carcinoembryonic antigen (CEA) and CA19.9 improves the diagnostic capability. Pancreatic cyst fluid CEA concentration of 192 ng/mL is generally the most agreed cutoff to differentiate mucinous from non-mucinous lesion. A fluid amylase level of <250 IU/L excludes the diagnosis of pseudocyst. Technical tips of EUS-FNA and the limitations of the procedure are discussed. Promising technique and FNA needle modifications have been described to improve the diagnostic yield at the cytopathologic analysis. The use of novel cyst fluid proteomics and deoxyribonucleic acid-based biomarkers of the PCLs are reviewed. Although it is considered a safe procedure, EUS-FNA is not a routine in every patient. Recommendations of the role of EUS-FNA at various common clinical scenarios are discussed.

Endoscopic ultrasound (EUS) has evolved to become a crucial tool for the evaluation of pancreatic diseases, among them solid pancreatic lesions. However, its ability to determine whether a lesion is malignant or not is difficult to establish based only in the endosonographic image. EUS-guided fine needle aspiration (EUS-FNA) allows obtaining a cytological and/or histological sample from pancreatic lesions, with a high overall accuracy and low complication rates. Although the clinical usefulness of EUS-FNA for pancreatic diseases is widely accepted, the indications for tissue diagnosis of pancreatic lesions suspected to be malignant is still controversial. This review highlights the diagnostic accuracy and complications of EUS-FNA, focusing on its current indications.

Subepithelial masses of the gastrointestinal (GI) tract are a frequent source of referral for endosonographic evaluation. Subepithelial tumors most often appear as protuberances in the GI tract with normal overlying mucosa. When there is a need to obtain a sample of the mass for diagnosis, endoscopic ultrasound (EUS) - guided fine-needle aspiration (FNA) is superior to other studies and should be the first choice to investigate any subepithelial lesion. When the decision is made to perform EUS-guided FNA several technical factors must be considered. The type and size of the needle chosen can affect diagnostic accuracy, adequacy of sample size and number of passes needed. The use of a stylet or suction and a fanning or standard technique during EUS-guided FNA are other factors that must be considered. Another method proposed to improve the efficacy of EUS-guided FNA is having an on-site cytopathologist or cytotechnician. Large or well-differentiated tumors may be more difficult to diagnose by standard EUS-FNA and the use of a biopsy needle can be used to acquire a histopathology sample. This can allow preservation of tissue architecture and cellularity of the lesion and may lead to a more definitive diagnosis. Alternatives to FNA such as taking bite-on-bite samples and endoscopic submucosal resection (ESMR) have been studied. Comparison of these two techniques found that ESMR has a significantly higher diagnostic yield. Most complications associated with EUS-FNA such as perforation, infection and pancreatitis are rare and the severity and incidence of these adverse events is not known. Controversy exists as to the optimal method in which to perform EUS-FNA and larger prospective trials are needed.

Endoscopic ultrasound (EUS) is one of the best diagnostic methods for diseases of the digestive tract and surrounding organs. Whereas EUS-guided fine needle aspiration (FNA) has been very useful for providing histological confirmation for previously hard to reach lesions, elastography is aiming to obtain a "virtual biopsy" by assessing differences in elasticity between the normal and pathological - usually malignant - tissue. A question that arises is whether EUS-elastography has reached a stage where it might successfully supplant the use of EUS-FNA in some of its clinical indications. The main indications of EUS-guided FNA are listed in this article and published data on the usage of elastography in these settings is reviewed for each one. In some of the indications, a plethora of studies have been published, notably for the evaluation of solid pancreatic masses and lymph nodes, while in others there is little relevant data (submucosal masses, left liver lesions, left adrenal masses), or elastography simply is not suitable as a diagnostic means (cystic lesions). Our conclusion is that elastography is not yet ready to replace EUS-FNA in its indications, but should complement it in various settings, especially for the assessment of lymph nodes. It can only be considered an alternative on a case-by-case basis, in situations where FNA is regarded as a contraindication. Furthermore, it could be used in conjunction with other imaging techniques, such as contrast-enhanced EUS, in order to further improve the accuracy of non-invasive EUS assessment, possibly making the case for a more limited or targeted use of EUS-FNA in selected cases.

Background and Objective: Endoscopic transmural drainage is an effective, but technically demanding treatment modality for walled off pancreatic necrosis (WOPN). The factors that determine the outcome of endoscopic treatment for WOPN have been infrequently studied. We aim to retrospectively correlate the morphological features of WOPN on endoscopic ultrasound (EUS) with the outcome of endoscopic transmural drainage. Patients and Methods: Over the last 3 years, 43 patients (36 males; mean age 36.04 ± 10.06 years) with symptomatic WOPN were treated by an attempted endoscopic drainage. The correlation between the morphological features of WOPN and the type of treatment offered as well as the number of endoscopic procedures undergone by the patient was assessed. Results: The mean size of WOPN was 9.95 ± 2.75 cm with <10%, 10-40% and >40% solid debris being present in 6, 33, and 4 patients, respectively. Patients with <10% necrotic debris needed only single session of endoscopic drainage, whereas patients with 10-40% solid debris needed two or more sessions. Patients with >40% solid debris either needed direct endoscopic debridement or surgical necrosectomy. The extent of necrosis correlated significantly (r = 0.703, P < 0.001) with the type of treatment received by the patient. With increasing size of the collection (r = 0.320, P = 0.047) and the amount of the solid debris (r = 0.800, P < 0.001), there was a significant increase in the number of endoscopic procedures required for successful outcome by the patient. Conclusions: The morphological features of WOPN on EUS have important therapeutic implications with collections having large size and more solid debris needing more aggressive therapeutic method for the successful outcome.

Background and Objectives: Cystic pancreatic lesions are a growing diagnostic challenge. The aim of this study was to proof a new diagnostic concept based on contrast-enhanced endoscopic ultrasound (CE-EUS) for differential diagnosis. Patients and Methods: A total of 125 patients with unclear cystic pancreatic lesions were included. The initial diagnostic was made by CE-EUS dividing the lesions in a group without contrast enhancing effect in the cystic wall, septae or nodule indicating pseudocysts or dysontogenetic cysts and a group with contrast enhancing effect in the described structures indicating cystic neoplasias. The investigations were performed using a Pentax echoendoscope and Hitachi Preirus ultrasound machine. The contrast enhancer used was 4.8 mL SonoVue ^® (Bracco, Italy). The group with suspected cystic neoplasia was referred for endoscopic fine-needle puncture for further diagnostic or treatment decisions. Results: The dividing of the groups by contrast-enhanced ultrasound was feasible because all (n = 56) suspected cystic neoplasias showed a contrast enhancing effect, whereas in only 4 from 69 pseudocystic or dysontogenetic cystic lesions a contrast enhancing effect in the wall could be observed. Endoscopic fine-needle puncture could diagnose all malignant neoplasias and relevant premalignant conditions. The long-term follow-up did not show any development of malignant cystic lesions. Conclusion: Using CE-EUS and endoscopic fine-needle puncture as diagnostic criteria seemed to be a feasible method to deal with different cystic lesions in daily practice.

Gastritis cystica profunda (GCP) is a rare pseudotumor of the stomach characterized by benign growths of deep gastric glands through the muscularis mucosae into the submucosa. We review a case of GCP in a 61-year-old patient with GCP, with emphasis on endoscopic ultrasound findings and present review of the current literature.