Cervical metastases from unknown primary tumor, paradigm changes. Review on clinical confrontation, study and treatment

Abstract

In adults, a cervical mass detected by physical examination or an imaging study may be the only manifestation of cancer from the head and neck. A delay in the diagnosis affects the prognosis of the disease, so there must be a high index of suspicion. Cervical metastases from unknown primary tumor (CUP) are metastatic tumors in which the diagnostic study failed to identify the primary site of cancer, with predominantly squamous histology. According to some studies, the most frequent origin was the oropharynx, including palatine tonsil and tongue base. Known risk factors are advanced ages, tobacco and alcohol consumption. Cu- rrently, human papilloma virus (HPV) infection is playing an increasingly important role as a risk factor, being the cause of between 20-25% of cancers of the head and neck. When confronting a patient with cervical mass it is important to carry out a complete anamne­sis and a thorough physical examination to detect any element suggestive of malignancy. Physical examination could be complemented with a flexible nasal endoscopic to evalua- te structures that can not be evaluated in the habitual examination. The search for the unknown primary can also be oriented based on lymphatic drainage patterns. Within the complementary evaluations, one can start with a study of images such as computed tomo- graphy (CT) or magnetic resonance imaging (MRI) with contrast, and also could consider ultrasound or PET/CT. If the primary can not be defined yet, fine needle aspiration (FNAP) can be the next choice and then a core biopsy that consisting of taking a sample from the center of the ultrasound-guided lesion, if necessary, including immunohistochemistry for HPV; both histological studies are preferable to an open biopsy because of the lower risk of complications. The next step searching for the primary includes endoscopic study and biop- sies under anesthesia. Regarding to the management of patients with CUP, it will depend on factors related to the stage of the disease: from surgery or radiotherapy (RT) only, surgery and RT, and in some cases chemotherapy. Frequent clinical follow-up is recommended du- ring the first years and images within the first 6 months after treatment.