First, the anesthesia colleague induces anesthesia and performs a rigid tracheobronchoscopy with 0° optics. The glottis, subglottis and trachea up to the entrance of the main bronchi show normal mucosal conditions, with no evidence of suspicious masses. After removal of the optics, intubation by the 1st surgeon. Flexible gastroesophagoscopy is then performed. The gastroscope is carefully advanced into the stomach under constant air insufflation. The stomach is then inspected and the mucosa is found to be normal in all areas, from the cardia to the pylorus. Then carefully withdraw the flexible gastroscope and inspect the esophagus from caudal to cranial, linea serrata and gastroesophageal junction 43 cm from the upper row of teeth. Caudal and middle part of the esophagus show slightly chronically altered mucosal conditions. Cranial ............................. of the esophagus are completely unremarkable. Then remove the flexible gastroscope and perform a direct pharyngoscopy using a size B small bore tube. After placing the mouth guard, carefully inspect the oral cavity and the oral vestibule. A relatively small, ulcer-shaped mass can be seen on the lower surface of the tongue paramedially on the right. On palpation, this grows endophytically into the body of the tongue. Next, inspection of the oropharynx. The soft and hard palate, palatal arches, posterior pharyngeal wall and base of the tongue are unremarkable. Switch to the size C small bore tube and inspect both piriform sinuses as well as the retrocricoidal area and supraglottis. Regular mucosal conditions here, no evidence of secondary malignancy. Removal of the small drainage tube without damaging the tooth and mouth structures. Placement of an oral retractor. The body and tip of the tongue are fixed with a suture and pulled out. The tumor is then exposed and the incision margins are marked at a distance of at least 1 to 1.2 cm from the tumor. After incision of the mucosa, careful suture marking was performed: 1st margin inferior, 3 o'clock long-long, 2nd margin lateral, short-long, 9 o'clock, 3rd margin medial, 9 o'clock, short-short. Then further dissection into the tongue musculature and maintaining the distance to the tumor of at least 1 cm. Careful dissection of the tongue muscles and careful hemostasis using ligatures and electrocoagulation. After removal of the tumor, a thin layer of muscle is removed caudally as a second sample. Both are sent for final histology. Careful hemostasis and securing of the Wharton's duct, which was not injured during the operation. Demonstration to <CLINICIAN_NAME> and discussion of the further procedure. Joint decision on primary wound closure. The wound edges are carefully adapted and the wound is closed primarily. Handover of the patient to the anesthesia colleagues. Completion of the operation without complications. Conclusion: A T1 squamous cell carcinoma of the lower surface of the right tongue is resected and an inconspicuous panendoscopy is performed in the same session without complications. Intraoperatively endophytically growing ulcer, 1 to 1.3 cm in size, which grows at least 3 to 4 mm into the body of the tongue. Resection with a distance of at least 1 cm in all directions. The tissue was sent for final histological analysis. Further procedure after receipt of the final histology. If tumor infiltration is more than 8 mm, a selective right neck dissection should be performed. Please allow soft food from the 2nd postoperative day. Continue antibiotics with clindamycin for the next 3 days.