Chordomas are malignant tumors that originate in embryonic notochordal remnants. The sacrum and skull are the most common sites; the mobile spine and other bones are extremely rare sites. We describe a 45-year-old man who presented with a lytic lesion in his left ilium. Imaging and pathology of a biopsy specimen suggested a malignant bone tumor; wide resection was accordingly performed. The morphology and immunohistochemistry of the operative specimen showed obvious characteristics of classic chordoma. To our knowledge, this is the first reported case of a chordoma originating in the ilium. Chordoma should therefore be considered in the differential diagnosis of lytic lesions in the ilium.
