First, inspection of the primary tumor region. As described above, this revealed an ulcerative lesion of the posterior floor of the mouth with infiltration of the posterior border of the tongue and superficial growth over the lateral border of the tongue to the lower surface of the tongue as well as extensive submucosal tumor extension dorsally to the base of the tongue, occupying a good 1/3 of the base of the tongue. CT diagnostics also show growth in a cervical direction with infiltration of the muscles of the floor of the mouth. The first step is to insert a PEG. This is done with the gastroscope under laryngoscopic control. Easy pre-scanning into the stomach, excellent diaphanoscopy, problem-free puncture of the stomach and subsequent placement of the PEG tube using the usual thread pull-through method and careful placement of the PEG plate in clearly cachectic patients. The patient is then repositioned and prepared for the transoral procedure. This is done with the open mouth retractor. Resection of the process with superficial growth in the area of the tongue edge and the underside of the tongue with a safety margin in the mucosa and at the basal level of a good 1 cm. Inclusion of the entire lateral floor of the mouth and resection in the area of the tongue going dorsally to the midline and here initially extending to the linea terminalis. The entire area of the lateral floor of the mouth, glossotonsillar groove, underside of the tongue, floor of the mouth and free edge of the tongue is now covered with marginal samples, all of which are diagnosed as tumor-free and dysplasia-free. The patient is now repositioned for the transcervical, submandibular incision procedure. Cut through skin and subcutaneous tissue. Dissection of the cranial and caudal platysma. First perform the neck dissection. To do this, expose and protect the sternocleidomastoid muscle, external jugular vein and auricularis magnus nerve. Exposure of the omohyoid muscle, release of the submandibular gland and exposure of the digastric muscle. Removal of the anterior neck preparation with careful protection of the facial vein, superior thyroid artery, hypoglossal nerve, cervical artery and with removal of some macroscopically suspicious ones in the jugulofacial angle, but without signs of environmental infiltration. Free dissection of the internal jugular vein with exposure and protection of the common carotid artery and vagus nerve. Exposure of the accessory nerve, clearing of the accessory triangle and careful completion caudally to level V with careful protection and exposure of the cervical plexus branches. Finally, if the wound is dry, extirpation of the submandibular gland and resection of the digastric muscle, both of which are not infiltrated. After gland removal, entry into the posterior floor of the mouth and achievement of enoral resection status. Now widen cranially. Displacement of the facial vein and artery. Exposure and later transection of the lingual artery, the hypoglossal nerve is initially preserved and exposed. It can now be seen that the nerve is directly infiltrated anteriorly by the tumor. There is also clear infiltration of the tumor into the muscles of the floor of the mouth. Extensive resection of the muscles of the floor of the mouth. Now by pulse.................................. of the tongue, a good overview is also obtained towards the base of the tongue and resection of the tumor with sufficient safety distance, especially in the area of the base of the tongue. En bloc and macroscopically in toto on the specimen. The remaining parts in the mucosal area are now also covered with margin samples. In the area of the dorsal base of the tongue, CIS is suspected in the frozen section diagnosis despite the macroscopically large safety margin. Therefore, a covering resection is performed here. Otherwise, in sano resection on all sides for the carcinoma. This results in a partial pharyngectomy and a hemiglossectomy on the right side with a total defect measuring 15 x 7 cm and a need for reconstruction. Neck dissection of the left side and tracheotomy are performed first. Neck dissection: cutting through skin and subcutaneous tissue. Corresponding to the opposite side. Separation and dissection of the platysma. Exposure of the sternocleidomastoid muscle, external jugular vein and auricular nerve. Exposure of the omohyoid muscle, release of the submandibular gland and removal of the capsule. Exposure of the digastric muscle. Removal of an anterior neck preparation with careful protection of the facial vein, the superior thyroid artery, the hypoglossal nerve and the cervical artery. Free preparation of the cervical vascular sheath with exposure of the common carotid artery and the vagus nerve. Exposure and preservation of the accessorius nerve, completion in the direction of level Va with careful protection of the cervical plexus branches. In conclusion, no suspicious conditions here. Careful irrigation of the wound. Insertion of a 10-gauge Redon drain and careful two-layer wound closure. Then perform the tracheotomy. To do this, make a horizontal incision approx. 1 cm below the cricoid cartilage with the larynx relatively high. Cut through the skin and subcutaneous tissue. Expose the infrahyoid musculature. Entering the infrahyoid musculature. Exposure of the anterior surface of the trachea. Exposure of the slender thyroid isthmus and transection. Insertion between the 2nd and 3rd tracheal ring. Creation of a wide tracheotomy. Successive suturing while performing the mucocutaneous anastomosis and finally problem-free reintubation to a size 9 low cuff cannula, which is suture-fixed. An antero-lateral transfemoral graft is then lifted from the right. After doppler sonographic identification of the main perforator and a secondary perforator, a medial incision is made after marking a graft measuring 15 x 8 cm in total. Medial transection of skin and subcutaneous tissue. Separation of the fascia lata. Exposure and securing of the rectus femoris muscle, widening of the incision, strictly subfascial release of the rectus femoris muscle and exposure of the pedicle vessel. Further incision of the graft, exposure of the main perforator, which has a small musculocutaneous course. Free preparation and exposure of the strong perforator from which both doppler sonographically marked vessels originate. Complete cutting of the graft, including the fascia lata. Isolation on the perforator and vascular pedicle. Removal of a muscle margin around the main perforator and removal of the vital graft and treatment of the feeding and draining vessels. Finally, careful wound inspection. Insertion of a 10-gauge Redon drain and strong multi-layer wound closure. This is followed by combined transcervical and transoral incorporation of the graft. Due to the extent of the graft, the conditions were somewhat more difficult, but in the end the conditions were intact on all sides and the reconstruction of half of the tongue was good, with the remaining tongue retaining its mobility. Conditioning of the vasa facialia. First, perform the arterial anastomosis with 8.0 Ethilon. This is successful and sufficient. Immediate regular and strong venous return flow via both draining veins. The facial vein is now anastomosed with the coupler system, once size 3.0, once 2.0. Finally, regular pedicle pulsation, positive spreading phenomenon and good graft perfusion so that a rubber flap is inserted and the procedure is carefully closed in two layers and completed. Conclusion: Intraoperative R0 resected cT4a cN2b oral cavity carcinoma, mainly in the right-sided tongue area. If the graft heals properly, the first attempts at swallowing and, if necessary, swallowing training can be started from the 8th to 10th postoperative day. Presentation in our interdisciplinary tumor conference for adjuvant therapy that is certainly indicated.