Introductory consultation with the anesthetist. Start of PEG insertion: For this purpose, insertion with the gastroscope under laryngoscopic control. Problem-free pre-laryngoscopy into the stomach. Excellent diaphanoscopy. Problem-free puncture of the stomach. Subsequent problem-free PEG insertion using the usual suture pull-through method. The esophagus is inconspicuous on the endoscopy and regular postoperatively. The primary tumor region is now inspected: an exophytic mass measuring approx. 4x2 cm with transition to the lateral floor of the mouth and a small tumor extension towards the anterior floor of the mouth can be seen in the area of the free edge of the tongue on the right. In addition, the glossotonsillar groove is reached. The tonsil is rough and scarred with a questionable tumor extension into the tonsil region. After radical exposure of the tumor, successive resection is performed with sufficient macroscopic safety margin. The tumor is resected using an electric needle and dissection technique. The tumor has grown relatively superficially with hardly any deep infiltrations in the area of the tongue and the floor of the mouth. Basally, a sufficient safety margin was maintained on all sides and successive resection was performed, including the free edge of the tongue on the right and the floor of the mouth with partial resection of the sublingual and submandibular gland. The transition to the base of the tongue itself is again free. Removal of the glossotonsillar groove and, in the case of a questionable tumor extension into the tonsil, removal of the tonsil with subtotal removal of the anterior palatal arch. Hemostasis by means of bipolar coagulation and ligation of stronger vessels. The tumor is now macroscopically visible on the specimen in sano-resected form. Slightly narrower margin in the area of the anterior floor of the mouth. A basal and anterior resection is performed here. The tumor is now completely imaged with margin samples. Residual carcinoma can be seen just submucosally in the area of the anterior floor of the mouth. In addition, CIS in the area of the lateral floor of the mouth and in the area of the dorsum of the tongue. Low-grade dysplasia in the area of the soft palate without higher-grade dysplasia, also in the intraoperative reclassification. A generous resection is now performed in the area of the anterior floor of the mouth and re-covered with a marginal specimen. Additional resection in the area of the lateral floor of the mouth and in the area of the edge of the tongue. The anterior floor of the mouth is now tumor-free with no high-grade dysplasia, the tongue margin is free with only minor dysplasia and CIS remains in the area of the lateral floor of the mouth. A new resection is performed here. CIS with additional evidence of invasive carcinoma is also seen here. Therefore, sharp incision of the alveolar ridge mucosa. Incision down to the periosteum. Removal of the entire mucosa and obtaining a generous, flat resection, which is then resected in a thread-oriented manner for frozen section diagnostics. The carcinoma in situ is found to have been removed in sano. Therefore, an R0 situation can be assumed overall. Due to the extensive enoral soft tissue defect involving the submandibular gland, a simultaneous neck dissection is not performed in this session. Also due to the extensive wound area and incipient swelling tendency, a supporting tracheotomy is performed. For this purpose, a horizontal skin incision is made below the cricoid cartilage. Cut through the skin and subcutaneous tissue. Expose the infrahyoid musculature. Entering the linea alba. Exposure of the cricoid cartilage. Exposure of the anterior surface of the trachea and transection of the thyroid isthmus. Insertion between the 1st and 2nd tracheal ring. Creation of a broad-based pedicled Björk flap and insertion of the tracheostoma. Subsequent easy intubation with a size 8 low cuff cannula, followed by careful and repeated irrigation of the enoral wound area. Meticulous hemostasis and termination of the procedure at this point if the enoral conditions are dry. Conclusion: Intraoperative R0-resected at least cT2 cN2b oral cavity carcinoma on the right with extensive perifocal dysplasia and perifocal CIS. Overall, extensive field carcinomatization can also be assumed here. The necessary neck dissection on both sides should be planned in the 2nd session in approx. 2 weeks. Primary secondary wound healing should initially be aimed for enorally. With proper enoral healing and proper food build-up, prompt decannulation should be possible. Postoperative consultation with the anesthesiologist.