What is the management of lax lesions (laxity or lesions) found during endoscopy?

Management of Subepithelial Lesions (SELs) Found During Endoscopy

Management of subepithelial lesions depends on size, histopathology, malignant potential, and presence of symptoms, with endoscopic ultrasound (EUS) serving as the critical next step for characterization and tissue diagnosis. 1

Initial Endoscopic Assessment

During the initial endoscopy, assess the following features to guide further management:

• Size, shape, mobility, and consistency of the lesion using closed biopsy forceps 1
• Pillow sign: A soft, mobile mass that indents when pressed suggests a lipoma (98% specificity) 1, 2
• Central umbilication in an antral mass 6-10 mm in diameter, located 2-6 cm from the pylorus along the greater curvature, suggests pancreatic rest 1
• Change patient position to assess whether the lesion represents extrinsic compression rather than a true intramural mass 1

Critical pitfall: Standard mucosal biopsies are often non-diagnostic because SELs are submucosal by nature and normal mucosa overlies the lesion. 1

Endoscopic Ultrasound (EUS) Evaluation

EUS is the method of choice for characterizing SELs and should be performed for all lesions except those with classic features of lipoma or pancreatic rest. 1, 2

EUS provides essential information:

• Layer of origin: Determines whether the lesion arises from muscularis mucosa, submucosa (3rd layer), or muscularis propria (4th layer) 1, 3
• Size measurement: Critical for determining malignant potential and management strategy 1
• Echogenicity: Hyperechoic lesions in the 3rd layer typically represent benign lipomas, while hypoechoic lesions in the 4th layer may represent GISTs 3, 2
• Margin characteristics: Irregular borders, cystic spaces, ulceration, or echogenic foci suggest higher malignant potential 1

Tissue Acquisition Strategy

For Submucosal Lesions (3rd Layer)

Use EUS-guided fine-needle aspiration (FNA), EUS-guided fine-needle biopsy (FNB), or advanced endoscopic techniques such as unroofing or endoscopic submucosal resection. 1

• Bite-on-bite "tunneling" biopsies using jumbo forceps (12-13 mm³) achieve diagnostic yield of 55-65% for submucosal lesions 1
• Bleeding risk: Up to one-third of cases with tunneling biopsies 1

For Muscularis Propria Lesions (4th Layer)

Lesions arising from muscularis propria should be sampled using FNB or FNA to differentiate GIST from leiomyoma, with structural assessment and staining to determine malignant potential. 1

Management Algorithm by Lesion Type

Lipomas and Pancreatic Rests

SELs with endoscopic appearance consistent with lipoma or pancreatic rest and normal mucosal biopsies do not need further evaluation or surveillance. 1

• Lipomas appear intensely hyperechoic on EUS, arise from the 3rd layer, and demonstrate the pillow sign 2
• Pancreatic rests have characteristic central umbilication and typical location 1

Small SELs from Muscularis Propria (<2 cm)

For SELs arising from muscularis propria that are less than 2 cm in size, surveillance using EUS should be considered. 1

• Gastric GISTs ≤2 cm have very low metastasis rates (0%) regardless of mitotic index 1
• Surveillance interval: Not explicitly defined in guidelines, but serial EUS monitoring is recommended 1

Gastric GISTs ≥2 cm

Gastric GISTs larger than 2 cm should be considered for resection. 1

• Risk of metastasis increases to 3% for lesions 3-5 cm with low mitotic index and 16% with high mitotic index 1
• Small intestinal GISTs: Even lesions <2 cm with high mitotic index carry up to 50% metastasis risk and warrant more aggressive management 1

Symptomatic or High-Risk Features

Subepithelial lesions that are ulcerated, bleeding, or causing symptoms should be considered for resection. 1

High-risk EUS features requiring resection include:

• Irregular borders 1
• Cystic spaces 1
• Ulceration 1
• Echogenic foci 1

Endoscopic Resection Techniques

Endoscopic resection should be limited to endoscopists skilled in advanced tissue resection techniques. 1

Available techniques based on lesion characteristics:

• Endoscopic submucosal dissection (ESD): For submucosal lesions not involving muscularis propria 1
• Submucosal tunnel endoscopic resection (STER): For submucosal lesions, with en bloc resection rates of 95% and complete resection rates of 98% 1
• Endoscopic full-thickness resection (FTRD): For lesions involving muscularis propria up to 20 mm in size, though technical success decreases for SELs ≥15 mm 1

Important limitation: FTRD has lower complete (R0) resection rates (68-76%) for gastric SELs compared to mucosal lesions, particularly for bulky lesions where slippage under overlying mucosa can occur. 1

Common Pitfalls to Avoid

• Do not biopsy vascular or cystic lesions until EUS evaluation is completed 1
• Do not rely on endoscopy alone to differentiate intramural lesions from extrinsic compression (sensitivity 89-98%, but specificity only 29-64%) 1
• Do not assume small size equals benign behavior for small intestinal GISTs, which have higher malignant potential than gastric GISTs of similar size 1
• Recognize that standard mucosal biopsies have poor diagnostic yield and may cause unnecessary bleeding 1