ABSTRACT
Cancer of unknown primary (CUP) origin is the seventh to eighth most frequent malignancy and the fourth commonest cause of cancer death. It accounts for 3% to 5% of all malignant neoplasms (1-3).
CUP is defined as a histologically confirmed diagnosis of malignancy in patients with unremarkable medical history and physical examination, with normal routine blood tests, urine and stool tests, noncontributory immunohistochemical investigation as well as normal chest X ray, abdominal and pelvic computed tomography (CT), or mammography in certain cases (4-6).
