After active patient identification, the patient is brought into the operating theater. Team time-out and induction of anesthesia by the anesthesia colleagues. The oropharyngoscopy is performed first. This reveals the tumor described above, which appears to be located in the area of the glossotonsillar groove. Ventral extension to the middle third of the anterior palatal arch. Subsequently transition to the glossotonsillar groove and into the base of the tongue. The tumor is relatively difficult to palpate as it grows largely submucosally in the area of the base of the tongue. Transition to PEG placement. The endoscope is inserted under visualization and air is constantly insufflated into the stomach. Here the gastric mucosa is inconspicuous on all sides. After a clear positive diaphanoscopy, the PEG tube is inserted using the thread pull-through method in the typical manner. This was performed without any problems. The patient was given 3 g Unacid preoperatively. The patient was then repositioned for transoral tumor resection. Insertion of the self-retaining Jennings retractor and suturing of the tongue. Luxation of the tongue and renewed palpatory identification of the tumor borders. Start of resection in the area of the anterior palatal arch with the electric needle. Resection down to the tonsil. As the tumor extensions are relatively close to the tonsil tissue, the decision is made to resect the tonsil en bloc as well. With constant palpatory identification of the tumor borders, the tumor is successively resected with a clinically macroscopically wide safety margin. In between, bipolar coagulation of small arterial bleedings is performed. The suture marking of the primary tumor is still performed in situ. The anterior margin of the posterior third of the tongue and the glossotonsillar groove as well as the margin of the anterior palatal arch and the medial base of the tongue are marked with sutures. Hemostasis by means of bipolar coagulation. Insertion of an H2O2-soaked hydrogen compress. In the meantime, the specimen has been sent for frozen section diagnostics. Repositioning of the patient for neck dissection. Superficial skin disinfection and sterile draping. Mark the planned incision from preauricular to infrolobular and curved towards the caudal side in a bayonet shape in the area of the sternocleidomastoid muscle anterior margin. Sharp transection of the cutis and subcutis. Exposure of the sternocleidomastoid muscle. Exposure and initial protection of the auricularis magnus nerve. Exposure of the omohyoid muscle as the cranial border as well as the submandibular gland and the digastric muscle as the cranial border. Turn to the cervical vascular sheath. Dissection of the internal jugular vein and the external and internal carotid arteries. Level II shows that the tumor infiltrates the sternocleidomastoid broadly. The decision was therefore made to resect the sternocleidomastoid muscle. This is done using the electric knife, initially caudally. Cranially, the metastatic conglomerate is firmly seated in level II b and appears to infiltrate the caudal parotid pole. The tumor extensions reach up to the carotid bifurcation. However, the tumor can be separated from the external carotid artery and the first branches as well as the internal carotid artery with the Reynold scissors. Exposure and protection of the vagus nerve. It is also apparent that the internal jugular vein is infiltrated cranially by the tumor. It was therefore decided to remove it as well. Double ligation of the same caudally and single ligation cranially. The tumor extends cranially under the digastric muscle. Therefore, removal of the same and lateral beating of the muscle belly. You now have a good view of the internal carotid artery and all external branches. Expose the superior thyroid artery, the lingual artery, the facial artery and the ascending pharyngeal artery. As the tumor also infiltrates the caudal parotid pole, the incision is extended cranially to secure the marginal ramus and the glandular capsule is exposed. Expose the cartilaginous pointer and the main facial trunk. Subsequently, successive dissection along the main trunk and exposure of the frontofacial and cervicofacial bundle. The cervicofacial bundle is dissected further into the periphery, carefully monitoring the marginal ramus. The laterocaudal part of the parotid gland is then removed while sparing the marginal mandibular nerve. The digastric muscle is also dissected dorsally. The same applies to the accessorius nerve, which is also located in the tumor conglomerate. After laborious dissection, the metastatic block can be removed in toto. Only in the area of the carotid bifurcation does a tumor remnant still appear to be present macroscopically. Therefore, meticulous dissection along the vessels and removal of the questionably infiltrated material. Despite the preoperatively small tumor extension, the tumor appears to grow diffusely infiltrating intraoperatively. The dissection extends as far as the pharyngeal musculature. No macroscopic tumor remnants here. Subsequent removal of the remaining medial and lateral neck specimen. Overall removal of levels II to V. Hemostasis using bipolar coagulation. Wound irrigation with H2O2 and NACL. Insertion of a Redon drainage as well as subcutaneous suture and skin suture. Application of a wound dressing. In the meantime, rapid incision announcement by telephone. Microscopic suspicion of R1 status in the area of the wound bed at the anterior margin of the posterior third of the tongue. The patient is therefore repositioned for transoral resection. The complete wound bed is resected and sent for definitive histology (resection of the wound bed of the posterior third of the tongue at the front and resection of the wound bed of the posterior third of the tongue at the back). Subsequently, definitive marginal samples were taken in the area of the wound bed (posterior third of the tongue at the front, posterior third of the tongue at the back). Extensive hemostasis using bipolar coagulation. Transfer of the patient intubated and ventilated to the local intensive care unit, as a tracheotomy had not been discussed and planned with the patient in advance. The operation was completed without complications. Conclusion: Due to the extensive and diffuse tumor growth, the patient should be advised to undergo adjuvant radiochemotherapy postoperatively.  