This is an investigator led prospective open label investigation, performed at three clinics in Sweden, comparing the flexible endoscopic biopsy instrument Endodrill Model X with the standard sampling method endoscopic ultrasound fine needle aspiration/biopsy. Assessment of safety is the primary objective and performance is the secondary objective.

The investigation will include 20 patients with lesions and suspected tumors in the stomach, esophagus or duodenum (upper small intestine). The investigation will consist of one visit with an endoscopic examination with sampling of an observed lesion or suspected tumor. Six biopsies will be collected from each patient, three consecutive samples using the Endodrill Model X instrument and three consecutive samples using the standard fine needle. The order of instruments to be used will be randomly assigned. The patient will be under observation for 2 hours after the procedure. Telephone follow-up will be performed 1 and 7 days after the examination. Visual confirmation of the biopsies size will be recorded at the examination. If the samples verify a tumor or not will be evaluated at Day 14 when the pathology report is concluded.

Inclusion Criteria:

• Adults at least 18 years of age at the day of inclusion
• Signed informed consent
• Submucosal tumor of the upper gastrointestinal tract with tumor size ≥ 10 mm, well localized by the endoscopic examination

Exclusion Criteria:

• Suspicion of vascular tumor (e.g. pulsating tumor)
• Ongoing treatment with anticoagulants (e.g. Warfarin)
• Ongoing treatment with immunosuppressive drugs
• Pregnancy

The order of the instruments to be used is blinded to the endoscopist until after the tumor has been visualized to avoid and minimize the influence of the choice of instrument of where the sample is taken. Closed envelopes prepared according to a randomization list stratified by site are available at each site. The envelope is opened by an assistant and not shown to the examiner until the tumor has been visualized.