Unusual Malignant Thoracic Cystic Lesion.

Malignant cystic lesions in the spine are rare. In this report, we present a 65-year-old man who presented with imbalance on walking of 1-week duration with intact motor examination. Magnetic resonance imaging of the thoracic spine showed large expansile, T2-hyperintense mass involving T8 vertebral body, replacing the posterior elements causing cord compression with associated edema. He underwent uneventful T8 corpectomy, placement of expandable interbody cage, and T5-T11 posterolateral fusion using bilateral transpedicular approach. However, he died 5 months later due to progression of moderately differentiated metastatic lung cancer. To our knowledge, this is the first report showing the near-complete replacement of vertebral body and posterior elements with a malignant cystic lesion.