This colloquium was the 38th Li'ege International Astrophysical Colloquium (38thLIAC -http: //www.ago.ulg.ac.be/APub/Colloques/Liac38) it was also held under the auspices of the European Helio- and Asteroseismology Network (HELAS - http: //www.helas-eu.org/), the CoRoT Evolution and Seismic Tools Activity (CoRoT/ESTA - http: //www.astro.up.pt/esta/) and the Belgian Asteroseismology Group (BAG - http: //www.asteroseismology.be). The first part of the conference was devoted to the internal structure of massive stars with session 1 dealing with the theoretical aspects of non standard physical processes while session 2 presented the challenges met in stellar modelling when introducing these physical processes. Session 3 was a state of the art in atmospheres, mass loss and stellar winds in massive stars. Session 4 presented the pulsation observations in massive stars while session 5 discussed the asteroseismic signatures of the physical processes involved in their internal structure. A final session 6 was essentially focused on the interpretation of the asteroseismic observations of ground-based, MOST and CoRoT target