[Clinical characteristics of 20 lung adenocarcinoma patients misdiagnosed as interstitial pneumonia].

This study retrospectively collected the relevant clinical data of patients with lung adenocarcinoma who were initially misdiagnosed as interstitial pneumonia at the First Affiliated Hospital of Zhengzhou University from April 2016 to October 2024. The clinical manifestations, laboratory tests, chest CT, misdiagnosis situations, treatment processes, and outcome in the patients were analyzed. A total of 20 patients were included, with 10 males and 10 females, aged (64.5±11.9) years. All 20 patients presented with cough, 15 had expectoration, 14 had chest tightness, 4 had fever, and 2 had chest pain. Carcinoembryonic antigen levels were elevated in 10 patients. There were 6 cases of the predominantly peripheral pleural type and 14 cases of the whole-lobe type. The lesions mostly manifested as ground-glass opacities, consolidation, or a combination of both. All 20 patients were initially misdiagnosed as interstitial pneumonia in the early stage and were later diagnosed with lung adenocarcinoma through lung biopsy or bronchoscopy biopsy for pathological examination. Four patients requested discharge without receiving treatment; 1 received symptomatic treatment; 1 was treated with a single immune checkpoint inhibitor, and the lesions progressed; 14 patients received chemotherapy-based comprehensive treatment, among them, 1 patient had a Kirsten rat sarcoma viral oncogene homolog (Kras) G12C mutation and was treated with sotorasib orally in combination with bevacizumab, achieving stable disease and remaining under follow-up. The median follow-up time for all patients was [M(Q1,Q3)]12.2 (6.8, 13.7) months. Nineteen patients died, and 1 survived. The median progression-free survival was 3.0 (95%CI: 0.3-5.7) months (range: 0.5-9.6 months), and the median overall survival was 12.2 (95%CI: 7.6-16.8) months (range: 0.7-20.4 months). Diffuse interstitial lung adenocarcinoma is clinically rare and prone to misdiagnosis as interstitial pneumonia. Its imaging manifestations mainly include predominantly peripheral pleural or diffuse bilateral lung ground-glass opacities. The diagnosis mainly relies on CT-guided lung biopsy for pathological examination. Patients have a poor prognosis. Kras mutation-related targeted drugs may improve survival, but large-scale clinical studies are needed for verification.