ABSTRACT
Carcinoma of unknown primary (CUP) is a metastatic malignant epithelial tumor (1). Lymph nodes are the most frequent sites (about one-third of the cases) with the anatomical site being, in order of frequency, cervical, mediastinal, retroperitoneal, and inguinal. Other major sites of CUPs include the liver, the bones, the lungs, and the brain. CUP belongs to a heterogeneous entity owing to the variety of histopathological types and sites of metastases. The primary site remains unknown in more than 25% of patients. Prognosis is usually poor with a median survival time of only few months (2-4).
