Interstitial lung diseases (ILDs) are frequently characterized by the presence of pulmonary fibrosis (PF), which may lead to respiratory failure secondary to irreversible parenchymal distortion. Although idiopathic pulmonary fibrosis (IPF) is the clinical prototype, the emergence of the progressive pulmonary fibrosis (PPF) phenotype has shifted the therapeutic paradigm toward shared pathogenic pathways while preserving the need to recognize the biological and clinical heterogeneity of the underlying ILDs. This state-of-the-art review integrates recent experimental and clinical data to provide a comprehensive overview of the transition from inflammatory models to the current epithelial-centric framework of fibrogenesis. In particular, the shift from ineffective anti-inflammatory strategies to the success of nintedanib and pirfenidone in both IPF and non-IPF progressive diseases is discussed. Furthermore, recent advances from phase II and III clinical trials targeting specific molecular drivers of fibrosis and vascular remodeling are analyzed, with a focus on pathway-oriented therapies, including nerandomilast, admilparant, and inhaled treprostinil. Understanding this molecular crosstalk is essential for the development of new therapeutic strategy based on precision medicine and it may support a new era of combination approaches aimed at stabilizing disease and improving patient outcomes in both idiopathic and progressive pulmonary fibrosis.

Background: Endosonography (i.e., endoscopic ultrasound with bronchoscope fine-needle aspiration, EUS-B-FNA and endobronchial ultrasound-guided transbronchial needle aspiration, EBUS-TBNA) is a widely used technique in the diagnosis and staging of non-small cell lung cancer. Limited data are available in diagnosing small cell lung cancer (SCLC), and no studies have specifically investigated the diagnostic accuracy of EUS-B-FNA in these patients. The study aims at evaluating the sensitivity and safety of endosonography in the diagnosis of SCLC. Methods: A prospective, single-center, observational study was conducted in Italy. All patients diagnosed with SCLC who underwent EUS-B-FNA and/or EBUS-TBNA were enrolled. The sensitivity of EUS-B-FNA and EBUS-TBNA were assessed using pathological confirmation as the gold standard. Results: A total of 72 patients (38 (53%) males) with confirmed SCLC were included in the study. EUS-B-FNA was performed in 31 (43%) patients and EBUS-TBNA in 44 (61.1%) patients; both procedures were performed in three (4.2%). The overall sensitivity of endosonography was 97.2%. The sensitivity of EUS-B-FNA and EBUS-TBNA was 96.8% and 90.9%, respectively. No differences were observed in the sensitivity of both techniques when sampling lymph nodes vs. pulmonary parenchymal lesions (p = 0.99). The overall complication rate was 5.6%. No major complications were reported. Conclusions: Endosonography is a highly accurate and safe technique in diagnosing SCLC. EUS-B-FNA alone demonstrates excellent sensitivity, supporting its extensive role as a valuable diagnostic tool. The combined use of both techniques may further optimize diagnostic yield in the diagnosis of SCLC.