Fig. 4
From: Understanding a mass in the paraspinal region: an anatomical approach
Longitudinal and transversal extension of three distinct paraspinal tumours. Spinal and paraspinal metastasis of urothelial carcinoma of the left upper tract in an 83-year-old female (a, b). Sagittal T1WI a shows the longitudinal extension of the tumour within the left psoas muscle from L2 to S1 level. Contrast-enhanced axial CT scan reconstruction (b) demonstrates the transversal extension of the mass within the retroperitoneum (arrowheads), causing ureteral stenosis (black arrow). Undifferentiated sarcoma of soft tissue in a 37-year-old female (c). Contrast-enhanced axial T1WI (c) shows pleural extension (arrowhead). Costal Ewing’s sarcoma in a 23-year-old male (d). Contrast-enhanced axial T1WI (d) shows an extension in epaxial muscles (white arrowheads), a pleural and intercostal extension (black arrowheads), a posterior mediastinum extension (white arrow) and an epidural extension via the intervertebral foramen (black arrow). Yellow stars show the epicentre of masses