Role of Endoscopic Ultrasound in Subepithelial Lesions (SELs)

Abstract

A subepithelial lesion (SET) is defined as a lesion, bulge or impression visible within the lumen of the gastrointestinal tract that is covered by normally appearing mucosa and usually found incidentally during routine endoscopy. Such a lesion could be either an intramural mass or an impression caused by extramural structures. The old terminology has recently been replaced by the term "subepithelial lesion" because intramural lesions may arise and can be located in any layer of the GI wall underneath the epithelium. The most common SELs are gastrointestinal stromal tumors (GISTs), leiomyomas, lipomas, granular cell tumors (GCTs), pancreatic rests and carcinoid tumors. The prognosis varies from benign to potentially malignant. While the majority of the lesions are considered benign, some tumors such as GISTs and carcinoids have a strong propensity for malignant transformation. Endoscopic ultrasonography (EUS) is the most accurate diagnostic method for distinguishing between extraluminal compressions and intramural lesions and plays a critical role in the detection and management of SELs. This is because EUS can reveal the precise sonographic nature of the lesion even though sometimes there are complex cases, which are difficult to diagnose by EUS alone. Performing routine biopsies and obtaining tissue samples for diagnosis can be difficult because SELs are located beneath the normal epithelial layer. Mostly, EUS allows the practitioner to extract an optimal tissue sample since it allows fine-needle aspiration (FNA) and fine-needle biopsy (FNB) both of which provide good results. With immunocytochemical staining, all these techniques increase the accuracy of the diagnosis. Evaluation of subepithelial lesions by means of EUS imaging will provide further characterization of the lesion to help guide us in appropriate differential diagnosis and further management. In this chapter, we provide a systematic EUS-guided approach to the diagnosis, management and later surveillance for SELs, as well as presenting updated diagnostic techniques that may help physicians to appropriately manage these subepithelial lesions.

Páncreas ectópico, diagnóstico diferencial de lesión gástrica subepitelial: Reporte de caso y enfrentamiento inicial

“…La resección endoscópica estará contraindicada también en aquellas lesiones muy cercanas a grandes vasos extraluminales dado que, actualmente, la capacidad de hemostasia endoscópica está limitada por falta de equipos apropiados y la dificultad para controlar el sangramiento de un vaso de gran calibre. Es siempre fundamental tener en consideración la experiencia de la persona que realizará el procedimiento para decidir el método de elección 20 .…”

The applications of miniprobe endoscopic ultrasonography in the diagnosis and treatment of colorectal submucosal lesions

“…1 The prevalence of these lesions on routine endoscopy is unknown, but their occurrence rate is rather frequent at 1% during these procedures. 2,3 This rate tends to increase with the growth of colonoscopy for colorectal cancer screening. The most common types of colorectal submucosal lesions include neuroendocrine tumours (NETs), gastrointestinal stromal tumours (GISTs), lipomas, vascular lesions, and cystic lesions.…”

“…3,5,6 However, mainstream studies have focussed on assessing the detection effects of EUS on submucosal lesions of the upper digestive tract. 2,7,8 The radial and sectorial EUS is not widely used for the submucosal lesions of the lower digestive tract, such as colorectal submucosal lesions, due to the limitations of conventional EUS, including inflexible large tip diameters and instrument rigidity.…”

“…There is scant data on certain aspects of the mEUS differentiating diagnosis and the management of colorectal submucosal lesions. Previous studies of mEUS only explored the applications of mEUS on a single tumour/submucosal lesion, and there is no systematic evidence on the comparison of the effects of mEUS across different submucosal lesions 2,[6][7][8][9][10][11][12][13][14][15][16] The current study was planned to evaluate the efficacy of mEUS for the diagnosis and adjuvant treatment of patients with colorectal submucosal lesions.…”