After induction of anesthesia by the anesthesia colleagues, rigid tracheoscopy is performed. Problem-free passage of the glottis and entry into the endotracheal cavity. The mucosal conditions are unremarkable on all sides up to the tracheal bifurcation. Subsequent problem-free intubation by the surgeon. Start with esophagogastroscopy: insertion of the endoscope under visualization and constant air insufflation into the stomach. This reveals a typical gastric mucosal relief with no evidence of a tumor. However, the gastric mucosa appears erosively altered on all sides. However, an ulcer cannot be visualized. Subsequently, inversion and inspection of the gastroesophageal junction. This also shows erosive changes in the mucosa, but no evidence of a tumor. Subsequently, desufflation and slow withdrawal of the endoscope with circular inspection of all sections of the esophagus. There is also no evidence of malignancy in the area of the esophagus. The surgeon then repositions the patient. Insertion of the mouth guard and insertion with the Kleinsasser B-tube. Adjustment of the endolarynx. In the area of the right vocal fold, there is an extensive leukoplakic mucosal change in the middle and anterior third. Adjustment of the endolarynx with the aid of support autoscopy and the surgical microscope. Subsequent removal of the leukoplakic change in toto under microlaryngoscopic control. Hemostasis by insertion of a suprarenin-impregnated swab. Subsequent inspection of the posterior commissure. This also appears unremarkable. Enter the piriform sinus on the right and left. This is lined on both sides by smooth mucosa and can be freely unfolded up to the tip of the piriform sinus. There is no evidence of a tumor either postcricoidally or in the area of the esophageal entrance. Subsequent inspection of the oropharynx and the oral cavity. In the area of the middle third of the left edge of the tongue, the exophytic mass described above is visible. This has a roundish configuration and grows exophytically. Posteriorly, the growth tends to become very superficial. Palpatorily, only the exophytic growing part infiltrates into the depth. The resection margins are then marked with an electric needle. Then excision biopsy in the sense of a partial tongue resection. This is done both with the electric needle in the superficial parts and with the pointed scissors and bipolar coagulation in the deeper sections. The tumor is removed clinically and macroscopically well within the healthy tissue. The tumor is thread-marked for definitive histology. A definitive margin sample is then taken in the area of the cranial resection margin and the anterior part is marked. Subsequently, extensive bipolar coagulation. If the wound bed is dry, adaptation of the resection margins with Vicryl 2/0 using the back-stitch technique. Intraoperative demonstration of the findings on <CLINICIAN_NAME>. Completion of the operation without complications. Conclusion: V.a. cT1 cN0 tongue margin carcinoma on the left. Clinical macroscopic R0 resection. 1. depending on the definitive histologic findings, a neck dissection on the left side should be discussed. 2. removal of a leukoplakia in the area of the anterior and middle third of the right vocal fold. 3. erosive gastritis as part of the esophagogastroscopy. Postoperative internal assessment recommended and initiation of treatment with proton pump inhibitors.