ACR Appropriateness Criteria® Radiologic Management of Pulmonary Nodules and Masses: Update 2025

This document addresses the management of pulmonary nodules and masses, a frequent and clinically significant finding in thoracic imaging given the prevalence and mortality burden of lung cancer. The document was developed and updated by a multidisciplinary expert panel through systematic review of peer-reviewed literature and supplemented as needed by expert consensus. Clinical variants considered in this document include stable solitary pulmonary nodules, enlarging nodules, centrally versus peripherally located nodules, nodules in patients with prior malignancy, and persistent ground-glass opacities suspicious for adenocarcinoma. For each scenario, available imaging and procedural options-such as follow-up CT, PET/CT, percutaneous or endobronchial biopsy, ablation, stereotactic body radiotherapy, and surgery-were systematically evaluated. Key recommendations emphasize the role of tissue sampling in enlarging or suspicious nodules, the selective role of PET/CT in characterization and treatment planning, and the importance of balancing diagnostic yield with procedure-related risks such as pneumothorax and hemorrhage. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.