Fig. 29

Exostosis and chondrosarcoma, respectively, on the right and on the left transverse processes of T10 in a 57-year-old male with hereditary multiple exostosis. The patient had been experiencing back pain for 2 months, a possible indicator of malignant degeneration of a chondroma into a chondrosarcoma. The patient presents with a right osseous outgrowth (black arrows), which has cortical and medullary continuity with the underlying bone as shown in coronal T1WI (a) and axial CT scan reconstruction (c). The cartilage cap of both exostosis and chondrosarcoma appears with intermediate signal on T1WI (a) and high signal on T2WI (d) and has ring and arc calcifications (arrowheads). The patient presents a left osseous outgrowth (white arrows), with rough cortex and cortical disruption (b, c) and with thick cartilage cap (3 cm, double arrow) on axial T2WI (d). Yellow stars show the epicentre of masses