ReviewsAccurate Assessment of Histologic Parameters That Impact Lung Cancer Staging Implications for the American Joint Committee on Cancer Eighth Edition TNM ClassificationButnor, Kelly J. MDAuthor Information From the Department of Pathology and Laboratory Medicine, University of Vermont Medical Center, Burlington, VT. Reprints: Kelly J. Butnor, MD, Department of Pathology and Laboratory Medicine, University of Vermont Medical Center, 111 Colchester Ave, ACC Bldg, EP2-120, Burlington, VT 05401. E-mail: email@example.com. The author has no funding or conflicts to declare. AJSP: Reviews & Reports: May/June 2018 - Volume 23 - Issue 3 - p 134-137 doi: 10.1097/PCR.0000000000000242 Buy Metrics Abstract The eighth edition of the American Joint Committee on Cancer TNM Classification represents a paradigm shift in lung cancer staging. Some staging parameters, such as the visceral pleural invasion, have not changed. Others are a significant departure from the prior edition, including tumor size used to assign T category, which for the first time is based solely on the invasive component, excluding any lepidic component. Understanding how to assess these histologic parameters will allow pathologists to contribute to the improved care of lung cancer patients through accurate pathologic staging. © 2018 Lippincott Williams & Wilkins, Inc.