Head and neck cancers of unknown primary (CUP) represent up to 10% of all cancers located in the head and neck. True cancers of unknown primary, which remain of undetected primary origin after a correct clinical, imaging, surgical evaluation, have a reported frequency of between 1% and 2%. Cancers of unknown primary of the head and neck are a diagnostic challenge, considering that their main clinical manifestation is represented by the appearance of lymph node metastases in the cervical region.
In general, the detection of cancers with an unknown starting point is late, difficult, with significant therapeutic failure. The diagnostic-therapeutic approach starts from the histopathological structure of the lymph node metastasis and continues with a correct and complete imaging evaluation.
In this review are presented the diagnosis and therapeutic challenges and importance of head and neck cancers with unknown primary.