Imaging in cervical nodal metastases of unknown primary

In patients presenting with a neck adenopathy from a clinically unknown primary, efforts should be made to localize the primary tumour, as this allows a more focused therapy. Imaging is helpful in identifying suspicious mucosal sites that should be further investigated endoscopically, including biopsy. In case no primary tumour is detected in the head and neck, a positron emission tomography (PET) study can be considered to search for an infraclavicular primary tumour. This article reviews the diagnostic value of computed tomography (CT), magnetic resonance imaging, PET and PET/CT in this clinical context.