Smoking-related intersticial fibrosis (srif): A new entity?

Introduction: SRIF was described as changes in lung parenchyma (hyalinized interstitial fibrosis, alveolar septal thickening, emphysema and respiratory bronchiolitis-RB) in lobectomy specimens from smokers with cancer and eventually by HRCT (ground-glass attenuation, reticulation and thick-walled cysts without traction bronchiectasis or parenchymal distortion) Objectives: To describe a group of SRIF patients as associated with interstitial lung disease (ILD) and/or emphysema Methods: Retrospective study on SRIF patients diagnosed in ILD consult since 2016 by HRCT. The variables included:age, sex, smoking habit, HRCT findings, spirometry, DLCO, pulmonary biopsy and diagnosis Results: 30 patients (28 ♂,2 ♀); mean age 69; 80% ex-smokers, 20% current smokers. All underwent HRTC with findings of SRIF and another ILD in most cases (Table 1). Spirometry pattern was obstructive in 11, non-obstructive in 3 and normal in 14. DLCO was low in 26 (mild 9, moderate 13, severe 4). Out of 4 pulmonary biopsies (1 transbronchial and 3 surgical) SRIF was found in the surgical ones. Final diagnoses: ILD 19 (Table 2), COPD and/or emphysema 17. In 17 patients SRIF was associated with other smoking related-ILD:9 CPFE, 5 RB-ILD, 2 pulmonary LCH, 1 RA-ILD. 21 patients were evaluated in ILD multidisciplinary meeting Conclusions: 1-Radiologists must consider SRIF on performing HRCT on smokers or ex-smokers. 2-SRIF may coexist with multiple HRCT patterns of smoking-related ILD