[Carcinoma of unknown primary : a not so rare entity]

Carcinomas of unknown primary (CUP) form a whole group of heterogeneous neoplasias. CUP are defined as metastatic epithelial tumors in which the initial work up has failed to detect the primary site. Their frequency is 3-5 % of the adult solid neoplasias. The prognosis is poor with a life expectancy of a few months (inferior to 1 year). The treatment depends on the histology and, particularly, on the metastatic localiza¬tion. Surgery with or without radiotherapy is the preferred treatment option for isolated lesions. Systemic chemotherapy (with platinum compound) will be recommended for multiple lesions. The genetic expression profile of tumor cells could be useful in the future to determine the site of the primary tumor and/or to offer the best therapy for each patient.