Abstract: Objective To investigate the significance of chest CT examination in single metastasic encephaloma.Methods 46 cases chest X-ray and CT examinations of occult lung cancer with single metastatic encephaloma were analyzed retrospectively.Results All 46 cases had positive image results in CT,including 11 cases(23.9%) with apex pulmonis cancer,15 cases(32.6%) with postcardial?paravertebral and azygos vein fossa cancer;18 cases(39.1%) with retroastophrenic angle cancer,and 2 cases(4.4%) with peribrochial cancer.But only 12 cases(26.1%) had abnormal image manifestation in X-ray,and none of them was helpful for diagnosis-making.Conclusion Chest CT examinations is useful for diagnosis of occult lung cancer.For a patient who is highly suspected to have metastatic encephaloma,if the chest X-ray manifestation is negative,chest CT may be a useful examination for the diagnosis-making.

Key words: occult lung cancer, CT, metastatic encephaloma