In this issue of Surgical Pathology Clinics, guest editor Dr. Alain Borczuk brings his considerable expertise to the topic of New Frontiers in Thoracic Pathology. Top experts provide new insights into emerging technology that will affect thoracic pathology in both neoplastic and non-neoplastic disease. This issue covers updates in the utilization of molecular testing in surgical pathology of lung cancer and mesothelioma, highlights uncommon tumors in the differential of common tumors, and shares new approaches to non-neoplastic disease, including new clinicopathologic entities. Contains 13 relevant, practice-oriented topics including silicosis and non-asbestos associated pneumoconiosis; pathology of COVID-19 lung disease; salivary gland type lung cancer; microsatellite instability, mismatch repair and tumor mutation burden in lung cancer; artificial intelligence in lung pathology; and more. Provides in-depth clinical reviews on new frontiers in thoracic pathology, offering actionable insights for clinical practice. Presents the latest information on this timely, focused topic under the leadership of experienced editors in the field. Authors synthesize and distill the latest research and practice guidelines to create clinically significant, topic-based reviews.