In the patient, an N3 metastasis of a moderately differentiated squamous cell carcinoma was histologically confirmed during a panendoscopy <2013>. No intraoperative evidence of primarius. In the staging performed, CT shows a left-sided tonsil asymmetry with increased enhancement in PET-CT in lateral comparison, otherwise no evidence of primarius or further metastasis. Extensive metastasis on CT with extension into the parapharyngeal space. Sonographic cN3 neck status. Now indication for completion of the CUP diagnosis and resection of the extensive metastasis on the left side.