The proper management of subepithelial lesions (SELs) depends on the size, histopathology, malignant potential, and presence of symptoms, according to a new American Gastroenterological Association clinical practice update published in Clinical Gastroenterology and Hepatology.
“SELs are found in 1 in every 300 endoscopies, and two-thirds of these lesions are located in the stomach,” explained Kaveh Sharzehi, MD, an associate professor of medicine in the division of gastroenterology and hepatology at Oregon Health & Science University, Portland, and colleagues. “They represent a heterogeneous group of lesions including nonneoplastic lesions such as ectopic pancreatic tissue and neoplastic lesions. The neoplastic SELs can vary from lesions with no malignant potential such as lipomas to those with malignant potential such as gastrointestinal stromal tumors (GISTs). The majority of SELs are small and found incidentally.”
Dr. Kaveh Sharzehi
The authors developed 10 clinical practice advice statements on the diagnosis and management of subepithelial lesions based on a review of the published literature and expert opinion.
First, standard mucosal biopsies often don’t reach deep enough to obtain a pathologic diagnosis for SELs because the lesions have normal overlying mucosa. Forceps bite-on-bite/deep-well biopsies or tunnel biopsies may help to establish a pathologic diagnosis.
Used as an adjunct to standard endoscopy, endoscopic ultrasound (EUS) has become the primary method for determining diagnostic and prognostic characteristics of SELs – such as the layer of origin, echogenicity, and presence of blood vessels within the lesion. It can also help with tissue acquisition.
For SELs arising from the submucosa, EUS-guided fine-needle aspiration and fine-needle biopsy have evolved as widely used methods for obtaining tissue. For SELs arising from muscularis propria, fine-needle aspiration and fine-needle biopsy should be used to determine whether the lesion is a GIST or leiomyoma. Using structural assessment and staining will allow for the differentiation of mesenchymal tumors and assessment of their malignant potential.
To remove SELs, multiple endoscopic resection techniques may be appropriate, depending on the layer of origin, size, and location, with the goal of complete, en bloc resection with no disruption to the wall or capsule of the lesion. These techniques should be limited to endoscopists skilled in advanced tissue resection.
SELs without malignant potential, such as lipoma or pancreatic rest, don’t need further evaluation or surveillance.
SELs that are ulcerated, bleeding, or causing symptoms should be considered for resection.
Other lesions are managed with resection or surveillance based on pathology. For example, leiomyomas, which are benign and most often found in the esophagus, generally don’t require surveillance or resection. On the other hand, all GISTs have some malignant potential, and management varies by size, location, and presence of symptoms. GISTs larger than 2 cm, should be considered for resection. Some GISTs between 2 cm and 4 cm without high-risk features can be removed by using advanced endoscopic resection techniques.
The determination for resection in all cases should include a multidisciplinary approach, with confirmation of a low mitotic index and lack of metastatic disease on cross-sectional imaging.
“The ultimate goal of endoscopic resection is to have a complete resection,” the authors wrote. “Determining the layer of involvement by EUS is critical in planning resection techniques.”
The authors reported no grant support or funding sources for this report. One author serves as a consultant for Boston Scientific, Fujifilm, Intuitive Surgical, Medtronic, and Olympus. The remaining authors disclosed no conflicts.