Clinical-Functional Discordance in Combined Pulmonary Fibrosis and Emphysema (CPFE) Associated with Squamous Cell Carcinoma: A Hybrid Case Report and Scoping Review.

Background: Combined Pulmonary Fibrosis and Emphysema (CPFE) is a distinct clinical entity associated with a high oncogenic risk. It is characterized by a "functional paradox"—preserved spirometric volumes (FVC) despite severe impairment in gas exchange (DLCO)—which frequently delays early diagnosis. Objective: To document a case of CPFE presenting with squamous cell carcinoma and to conduct a Scoping Review to map the global evidence regarding the histological profile and functional characteristics of this association. Methods: A hybrid observational design was employed. (1) A CARE-compliant case report of an 82-year-old patient. (2) A PRISMA-ScR compliant scoping review searching PubMed, EMBASE, LILACS, and Google Scholar for observational studies on CPFE and lung cancer. Significance: This study aims to validate whether the "functional paradox" observed in clinical practice is a consistent global feature that complicates oncological screening in heavy smokers.