Initially induction of anesthesia, tracheoscopy performed. Unremarkable conditions in the trachea to carina area. Followed by transoral, endotracheal intubation. Positioning of the patient by the surgeon. A flexible esophagoscopy is performed using an endoscope, which is carefully advanced to the stomach under visualization. Inconspicuous conditions in the area of the entire oesophagus and stomach. Endoscopic inversion and inspection of the oesophago-gastric junction, with unremarkable findings. Retraction of the endoscope and performance of a rigid laryngo- and pharyngoscopy using a Kleinsasser C-tube. The endolarynx was completely unremarkable, the right piriform sinus, posterior wall of the hypopharynx and the postcricoidal region were unremarkable. In the area of the left piriform sinus and on its lateral wall, a tiny, spherical, exophytic mass covered by smooth mucosa was found, which was sent for an excisional biopsy for intraoperative frozen section examination. Subsequent inspection of the rest of the pharynx. The oropharyngeal region is completely normal. Samples are then taken from the right and left middle of the base of the tongue and hemostasis is performed using monopolar coagulation. Placement of the oral retractors and subsequent tonsillectomy, initially on the right side. Parauvular incision. Exposure of the upper pole. Hemostasis using bipolar coagulation. Exposure of the correct layer, capsular approach from cranial to caudal while sparing the anterior and posterior palatal arch. Deposition of the tonsil preparation in its lower pole, hemostasis there using bipolar coagulation. Subsequently, identical procedure on the left side. Parauvular incision, exposure of the upper pole, hemostasis there using bipolar coagulation. Exposure of the right capsular layer, dissection along the tonsil capsule from cranial to caudal. Hemostasis in the caudal pole using bipolar coagulation and placement of the tonsil preparation in the lower pole. Dry conditions. The right tonsil and the sample from the left hypopharynx are sent for intraoperative frozen section. The remaining samples were sent for final histology. The intraoperative frozen section examination resulted in a positive finding (G3 squamous cell carcinoma) in the area of the left hypopharynx. The findings were adjusted using a Kleinsasser C-tube and the laser beam was set to a power of 4 watts in continuous mode. Moving around the findings using the CO2 laser. Removal of the sampling region in toto. Subsequently, 3 marginal samples (anterior wall of the piriform sinus, median wall of the piriform sinus, lateral wall of the piriform sinus) which are sent for final examination. Hemostasis there using monopolar coagulation. Removal of the Kleinsasser tube and subsequent repositioning of the patient for the planned neck dissection on the left side. Application of local anesthesia there after skin spray disinfection. Ablate the skin, sterile draping. Make an incision along the anterior edge of the sternocleidomastoid muscle. Cut through the subcutaneous tissue and the platysma. Exposure of the anterior border of the sternocleidomastoid muscle, exposure of the accessorius nerve, exposure of the omohyoid muscle, exposure cranial to the posterior venter of the digastric muscle. A large metastasis is already visible in this area. Dissection of the metastasis from the accessorius nerve, the internal jugular vein and the facial vein as well as from the posterior venter of the digaster muscle. Removal of the same in toto. Subsequent dissection along the cervical vascular sheath from caudal to cranial. Protection of the cervical vascular sheath structures. Successive removal of the posterior neck specimen while sparing the plexus branches. This revealed several metastases. Removal of the anterior neck specimen, where further metastases were found. Dry conditions. Treatment of region V with multiple ligatures to avoid a chyle fistula. Dry conditions. Wound irrigation with hydrogen peroxide and Ringer's solution. Repeated inspection. Placement of a 10-gauge Redon drain. Two-layer wound closure. Completion of the procedure without complications. Conclusion: CUP panendoscopy, laser resection of a cT1 G3 hypopharyngeal carcinoma on the left side confirmed by intraoperative frozen section, modified radical neck resection while sparing the internal jugular vein and the accessory nerve and sternocleidomastoid muscle. Please plan PEG placement and prompt presentation of the patient to our interdisciplinary tumor conference for further planning (cave: M1 situation pulmonary left).