Locations of HL CNS involvement. (A) Tumor in the dorsal part of the thoracic spinal canal and (B) ventral part of the lumbar spine (T2-weighted MRI sequences of the same patient, red arrow indicating tumor location), (C) tumor originating from the skull (bone window with subtle osteolysis, and (D) PET-fusion demonstrating the same lesion as in panel C extending into orbit and middle cranial fossa.