Intravertebral spinal neurenteric cysts: a unique radiographic sign--"the hole-in-one vertebra".

A well-defined circular defect in the midst of a complex vertebral anomaly, visible on a plain radiograph, is diagnostic of an intravertebral extension of a neurenteric cyst. It may represent a connecting stalk between a mediastinal cyst and an intraspinal lesion. The "hole-in-one" vertebra is an indication for a magnetic resonance imaging (MRI) scan. When surgical excision of a mediastinal cyst is undertaken, the intravertebral tract should be curetted to avoid recurrence.