First, the patient is brought into the operating room, identified and the team time-out is carried out in the usual manner. Then induction of anesthesia by the anesthesia colleagues. Then tracheoscopy by the surgeon. In the area of the endolarynx, vocal fold level, subglottic to the trachea and carina, mucosal conditions are unremarkable on all sides. Subsequent intubation of the patient by the anesthesia colleagues. Head reclination by the surgeon and insertion of the flexible esophagogastroscope. Careful endoscopy into the stomach. Mucosal conditions in the stomach and esophagus are normal on all sides. Then insertion with the size C small bore tube. Careful endoscopy into the oropharynx. In the area of the soft and hard palate as well as the tonsil region, the mucosa is normal on all sides. The mucosa is also normal at the base of the tongue, epiglottis and vallecula. The piriform sinus is freely unfoldable and inconspicuous on both sides, as are the postcricoid region and the endolarynx. Subsequent insertion of a Jennings blocker. Tongue suture and disluxation of the tongue for closer inspection of the tongue edge and the underside of the tongue. A large, histologically confirmed carcinoma measuring approx. 1 x 1 cm was found in the area of the underside of the tongue on the right. Demonstration of the findings on <CLINICIAN_NAME> and successive excision with half a centimeter safety distance to the macroscopically visible tumor border using a monopolar needle. In the area of the epithelium in depth, carefully dissect further with plastic forceps and scissors and cut out the tumor while maintaining the safety distance. The tumor is thread-marked for frozen section examination. Careful hemostasis using bipolar forceps in the area of the tongue muscles; no macroscopic evidence of further tumor invasion in the wound area. Following notification of an R0 situation by the pathology colleagues and after consultation with <CLINICIAN_NAME>, the decision was made to perform a further resection in the area of the cranial wound base towards the tip of the tongue, as there is a close R0 situation here at 12 o'clock. An arcuate, final margin trial is also performed in the area from 9 to 3 o'clock. The post-resection and marginal sample are both thread-marked for final histology; please note this. Conclusion: Overall unremarkable panendoscopy and resection of the histologically confirmed carcinoma on the underside of the tongue without complications. According to the frozen section, there is an R0 resection on all sides; however, please note the resection and the final margin sample and present the patient to the tumor conference, if necessary, order an ultrasound for regional neck status documentation.