Primary alveolar soft part sarcoma of vertebra: a case report and literature review.

Alveolar soft part sarcoma (ASPS) is a rare malignant soft tissue tumor, which rarely occurs in bone. We present a case of ASPS in a 23-year-old man with a 2-month history of back pain. Computed tomography scanning and magnetic resonance images demonstrated a destructive process in the 12th thoracic vertebra associated with a unilateral soft tissue mass. The tumor showed evidence of hypervascularity on MRI; it obviously was enhanced on T1-weighted images after injection of Gd-GDPA, and signal voids were shown on all pulse sequences which may help to differentiate ASPS from other tumors of the vertebra. We believe that this is the first case of ASPS arising in a vertebra.