Email Post: Expert’s comment concerning Grand Rounds case entitled “Surgical management of recurrent thoracolumbar spinal sarcoma with 4-level total en bloc spondylectomy: description of technique and report of two cases” (by Claudia Druschel; Alexander C. Disch; Ingo Melcher; Tilmann Engelhardt; Alessandro Luzzati; Norbert P. Haas; Klaus-Dieter Schaser)