Endoscopic submucosal dissection (ESD) is the technique that has replaced surgery in the treatment of early neoplastic lesions of the stomach (LNPS). ESD of LNPS allows: a) less invasiveness compared to surgery; b) greater chances of "en bloc" resection and R0 resection compared to mucosectomy for lesions larger than 15 mm. Recent 2015 ESGE guidelines provide precise recommendations for the use of ESD in the treatment of LNPS, but Italy lacks prospective data on the efficacy and safety of ESD in a large sample of patients. A multicenter prospective observational study to create a database on the use of ESD in LNPS is essential to provide information regarding the efficacy and safety of ESD in Italy. This database would also provide information regarding the criteria applied in the use of ESD in the treatment of early gastric neoplasia

Inclusion Criteria:

• Age > 18 years old
• Endoscopic and histologic diagnosis of gastric superficial neoplasm that can be treated by ESD according to ESGE guidelines.
• Gastric neoplasm outside of latest ESD guidelines criteria in patients unfit for surgery

Exclusion Criteria:

• Final diagnosis of non neoplastic lesion.
• Gastric neoplasm outside of latest ESD guidelines criteria in patients fit for surgery
• Evidence of muscolar layer invasion or limph nodes or other organs metastasis at EUS or TC when performed.

All patients with gastric superficial neoplasms that can be treated by ESD according to ESGE guidelines or with gastric neoplasm outside of latest ESD guidelines criteria that are unfit for surgery.