Remarkable advances have occurred since the 3rd Series Fascicle published in 1995 with paradigm shifts in every dimension of our understanding of lung tumors including clinical, radiologic, histopathologic, cytopathologic, immunohistochemical, molecular and therapeutic aspects. The molecular revolution leading to effective targeted therapies and breakthroughs in immunotherapy for lung cancer have led to novel approaches incorporating the concept of personalized medicine for patients who historically had little hope. These advances have strengthened the place of pathologists to play a central role in the multidisciplinary team that is now needed to properly diagnose and manage lung cancer patients.