Diagnostic exam results for case 2. Chest unenhanced CT (A) and T2-weighted MRI (B) showed a well-defined and round mass located in the paravertebral sulcus without invasion of the vertebral body or intraspinal canal. The microscopic appearance of the tumor is shown (C). It was a hypercellular, fascicular spindle cell neoplasm; the cells within the lesion had tapering nuclei and pale, indistinct cytoplasm (low-power view). Within these overtly malignant areas, numerous large, bright eosinophilic rhabdomyoblasts were seen (high-power view).