<prompt> Most common posterior mediastinal tumour isDermoidNeurofibromaLipomaLymphoma  <response>: The most common tumour of posterior mediastinum is neurofibromas,which constitutes around 75 of the total.Other tumors include ganglioneuromas,aneurysm of descending aoa,lymph node mass. Reference:SRBs manual of surgery,5th edition,page no:1126. 