First, after insertion of the mouth guard, re-inspection of the tumor region with the Kleinsasser microlaryngoscope. Now resection of the tongue tumor from the enoral side after insertion of the mouth guard, starting at the tip of the tongue, almost in the median line dorsally with the monopolar. The mass, which on the surface only appears as a small ulcer on the left side between the edge of the tongue and the floor of the mouth, shows extensive infiltrative growth in depth and spherical growth towards the body of the tongue. The tumor is now gradually bypassed dorsally towards the base of the tongue and resection is now performed in the area of the base of the tongue towards the floor of the mouth. Here, the tumor is also bypassed with an appropriate safety margin. The tumor also shows a cone-like growth in depth, which is carefully bypassed and lifted accordingly. The neck is now dissected, first on the left side. To do this, make a skin incision along the anterior edge of the sternocleidomastoid, ending in a skin fold. Dissection of the platysmal flap and dissection of the sternocleidomastoid anterior edge. Exposure of the vascular nerve sheath and further dissection along the omohyoid muscle to the hyoid bone. Dissection along the digastric muscle towards the base of the skull and removal of levels II, III and IV. Level V is then removed, as there are two macroscopically conspicuous lymph nodes in level IIa. All vascular and nerve structures in the neck area are spared after exposure and re-embedding of nerves X, XI, XII. This is followed by exposure and re-embedding of the marginal ramus and mandibular nerve and dissection and removal of level Ib, including the submandibular gland. This results in a thorough effect in the complete removal of the basal margin of the tumor. The large penetrating defect is used in the further course of the reconstruction, the pedicle pull-through. This is followed by neck dissection on the right side. The skin incision is the same as on the left. Dissection of the platysmal flap and exposure of the vascular nerve sheath. Careful evacuation of level II, III and IV without evidence of macroscopically conspicuous lymph nodes. Redon drainage is inserted here, subcutaneous and skin sutures are used. N. hypoglossus, N. accessorius and N. vagus are exposed and re-embedded. The next step is to lift the forearm graft after carefully measuring the tissue to be lifted. The graft is marked accordingly on the forearm, prepared and lifted from distal to proximal. The lifting ends in the area of the crook of the elbow and the superficial and deep venous system is taken along. The radial ramus superficial nerve is exposed and spared during dissection. The tourniquet is opened and careful hemostasis is performed. The graft is then removed and incorporated enorally to reconstruct the tongue and floor of the mouth. After appropriate incorporation, the vessels are anastomosed in the sense of an end-to-end anastomosis of the superior thyroid artery with the radial artery and end-to-end anastomosis of the flap vein with a branch of the facial vein using a size 3.0 coupler. Checking the vascular flows, which are excellent, and finally subcutaneous sutures and skin sutures here too. The lifting defect in the area of the right forearm is covered with full-thickness skin, which is lifted in the area of the right groin, and partially closed primarily. Application of a vacuum dressing and a Kramer splint to immobilize the forearm. The groin wound is treated with a Redon drain and closed primarily with subcutaneous sutures and skin sutures. After re-inspection of the findings, minimal swelling and a completely clear airway, a tracheostomy is not performed at this stage. This may have to be done secondarily. The vascular signals to be duplicated are drawn in the neck area.