A routine chest X-ray in a 52-year-old man revealed a widening of the posterosuperior mediastinum and the patient was hospitalized on the suspicion of having a mediastinal mass lesion. Further investigations revealed an anterior cervicothoracic meningocele (intrathoracic meningocele), the dural herniation passing through two large midline congenital openings of the C7-T3 vertebral bodies which appeared partially fused and associated with other regional skeletal malformations.