First, anesthesia induction by the anesthesia colleagues. Followed by tracheoscopy. This reveals inconspicuous mucosal findings in the entire tracheal and laryngeal area. Now orotracheal intubation by the surgeon. Subsequent orohypopharyngoscopy and esophagoscopy as well as nasopharyngoscopy. A slight mucosal flap is seen at the base of the tongue. To be on the safe side, a marginal sample was taken, which was sent for final examination. No suspicion of malignancy here. Subsequent examination of the enoral area. Here, the flat change suspected of being malignant can be seen from the tip of the tongue on the right to the transition to the base of the tongue, passing over to the floor of the mouth, not exceeding the caruncle towards the middle. In addition, a leukoplakia-like change on the left tongue surface at the back of the tongue. A deep sample biopsy was taken in the area of the exophytic tumor. A marginal sample was also taken from the dorsum of the left tongue. Both are sent for frozen section. In the frozen section, change on the dorsum of the tongue, without evidence of malignancy. Carcinoma in situ with transition to invasive carcinoma at the edge of the tongue. Indication for partial resection of the tongue. The tongue carcinoma is incised macroscopically just under 1 cm in healthy tissue. Resection is carried out basally over a width of up to 1 cm. Resection includes the right half of the tongue and the floor of the mouth. Wharton's duct is partially resected in the distal area. The tumor is removed and marked with sutures, especially basally. Then circular frozen sections are taken, four in total. These are also thread-marked and sent to the frozen section. In the frozen section, both the tumor in the basal direction and the mucosal borders are not infiltrated by tumor after examination of the marginal samples. Thus R0 resection. Careful hemostasis is performed. Part of the lingual artery was bypassed in the tongue body area. The wharton's duct was incised at the junction of the distal middle meatus and sutured laterally to the remaining alveolar ridge mucosa. Subsequent careful hemostasis and irrigation. The procedure was completed without complications. As the resection had not spread to the base of the tongue and deeper oropharyngeal areas and was relatively superficial, a tracheotomy was not performed. Due to the cN0 status, waiting for the final histology, then discussion of neck dissection again.