Conflict of Interest Funding/Support: This project was supported by the University Hospital of Poitiers, France. This study did not benefit from financial support. Role of the Funder/Sponsor: University Hospital of Poitiers, France, had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication. Data Sharing Statement: See Supplement 2. Additional Contributions: We acknowledge Cynthia Bordage, RN, Bertrand Drugeon, MD, Amélie Mabille, MD, Nicolas Marjanovic, MD, Severine Mousse, MSc, Alexandre Rahoui, MD and Camille Raynaud, MD, who assisted in data collection and patient follow-up, Pierre Dupuis, PharmD, who performed the biochemical tests, and Jeffrey Arsham for editing assistance, all from the University hospital of Poitiers, France. There was no financial compensation for these contributions. OBSERVATION Adolescent Presentation of Nasal Chondromesenchymal Hamartoma: A Case Report and Literature Review Nasal chondromesenchymal hamartoma (NCMH) is a very rare benign tumor of the nasal cavity and paranasal sinuses that usually presents in infancy. These tumors may be expansile and locally destructive. The etiology has remained unclear, but it has been linked in the past to pleuropulmonary blastoma as