Endoscopic management of submucosal tumors

Submucosal tumors (SMTs) of the gastrointestinal (GI) tract are lesions originating from the submucosal layer or deeper wall layers. While many SMTs are benign (e.g., lipomas, leiomyomas), others may harbor malignant potential, such as gastrointestinal stromal tumors (GISTs). Endoscopic management has emerged as a minimally invasive alternative to surgery for select cases, offering reduced morbidity and faster recovery.

Indications and Preoperative Evaluation
Endoscopic resection is suitable for SMTs <3 cm in diameter, located in the submucosa or superficial muscularis propria, and without signs of metastasis. Preprocedural evaluation includes endoscopic ultrasound (EUS) to assess tumor size, layer of origin, and echogenicity. Contrast-enhanced imaging (CT/MRI) may complement EUS to exclude malignancy or lymph node involvement.

Techniques
Endoscopic Submucosal Dissection (ESD): Used for tumors confined to the submucosa. A submucosal fluid cushion is created, followed by circumferential incision and en bloc resection.
Endoscopic Full-Thickness Resection (EFTR): Suitable for lesions involving the muscularis propria. The tumor is resected along with the GI wall, followed by closure using clips or suturing devices.
Submucosal Tunneling Endoscopic Resection (STER): A tunnel is created in the submucosa to access and remove tumors (e.g., esophageal or gastric SMTs), minimizing mucosal damage.

Advantages and Challenges
Endoscopic techniques preserve organ integrity and reduce postoperative complications compared to surgery. However, technical challenges include risk of perforation, bleeding, and incomplete resection, particularly for tumors with deep muscularis propria involvement. Mastery of advanced hemostasis and closure techniques (e.g., over-the-scope clips, endoscopic suturing) is critical.

Postprocedural Care and Follow-Up
Patients require short-term observation for complications. Histopathological analysis confirms tumor type and margin status. For GISTs, immunohistochemical staining (e.g., CD117, DOG1) guides further management, including adjuvant therapy. Surveillance endoscopy or imaging is recommended to detect recurrence.

Conclusion
Endoscopic management of SMTs is a safe and effective option for carefully selected cases. Ongoing advancements in endoscopic tools and techniques continue to expand its applicability, emphasizing the importance of multidisciplinary decision-making involving endoscopists, surgeons, and oncologists.