Submucosal Tumor Removal by Endoscopic Excision Therapy

Smaller submucous tumors in the stomach are usually seen as a random finding in gastroscopies and present a diagnostic dilemma to the doctor and patient: type specification is usually unclear whether it is an absolutely benign (without degeneration potential) or a malignant or prone tumor (usually gastrointestinal stromal tumor, GIST). However, this is crucial for further management. In endosonographic imaging there are only approximate values in the differential diagnosis between GIST and non-GIST, the endoscopic biopsy is too superficial, and the hit rate of endosonographic pin puncture is limited, and in most studies is less than 70% Therefore, one can only make assumptions and create a risk profile from imaging and tumor size (limit size 3 cm, partly also 2 cm). Both follow-up recommendations (rather no GIST) and laparoscopic surgical removal (proven or probable/possible GIST) are not rarely without clear preference, especially for smaller tumors. For these indications, a simple endoscopic removal option comparable to the polypectomy in the colon (where no histological type diagnosis is made before) does not exist. Previous studies are usually subject to bias in several directions: 1. The frequency of GIST tumors among submucous tumors/lesions (SMT) in the stomach is unclear. Gastroenterological series always contain smaller GIST tumors, but are reported almost exclusively from clinics. The rate of these tumors in the overall collective of patients seen in the field of (mostly established) gastroenterologists is thus completely unclear. Surgical or oncological series have usually included more aggressive tumors consisting mainly or exclusively of GIST tumors, therefore do not allow epidemiological conclusions. 2. If no surgery is performed (and thus a definitive histology is forced), only information from follow-up examinations remains. Previous follow-up studies show the dilemma of insufficient differential diagnosis of lesions by endosonography and (endosonographic or other) biopsy, which usually have insufficient accuracy. In addition, the follow-up time in the studies hardly extends beyond 2 years. The "gastroenterological gut instinct" that these small lesions are not dangerous may be true, but is not proven.